Aquarium Fish Nutrition |
The content of this article has been updated regularly, often monthly, to be as up to date as possible citing other's research too (including another fish food expert/guru Clay Neighbors).
The content is based on part on my extensive observations as well as tests in fish nutrition dating all the way back to 1978 utilizing my 1000s of client aquariums I had under contract, including the Bahooka Restaurant with over 110 custom aquariums where I had complete control of feeding and therefore was easily able to take notes in in trials of different methods and long term results (since I maintained these aquariums for years).
I also attended seminars along with professional trade shows and allowed mentoring by others who had more expertise. During my early years I earned the nickname "Green Flake Man" at these trade shows for my research into fish food, in particular those with high amounts of Spirulina Algae.
Where this article differs from most all others is this information and research dates back several decades and ALL recommendations (& fish food developments) are based on this in depth research. This is UNLIKE most articles that are written after so as to support the latest marketing scheme for a premium fish food. I know of NO other article that can make this claim.
For those who might make Ad Hominem attacks as to this article promoting certain fish foods over others; it would be dishonest of me to do otherwise after my decades of research and experience. The time line of this article also disproves these dishonest critics, since this article at it's roots dates back to 1978, long before many suggested foods even existed. Even online, this article dates back to 2005 with 100s of revisions and changes in recommendations as the knowledge base grows.
In the early years of my research this article is based from, "quality of ingredients" was the bar many prepared fish foods needed to overcome.
However in more recent years, most premium fish foods have overcome this bar and now the bar is "fish food analysis" where the majority of fish foods (including premium brands) still are lacking due to cooking process, too high energy levels, & too low fiber content (which many attempt to make up for with probiotics).
This article is primarily about prepared fish foods. Near the end of this article I do discuss some live, frozen and freeze dried foods.
Regardless of whether the fish' diet is 100% prepared or prepared that is supplemented with live/frozen (which I have had test fish do very well in controlled tests on 100% prepared foods), you want to seek a fish food that has the lowest amount of supplementation as well as one that is optimized as per energy points, fiber, and proteins to make the food viable diet. This fact has been proven in human nutrition too.
Any prepared fish food that has to add vitamin, mineral, and other supplements to bring their food up to higher standards is obviously not providing these via optimal ingredients and/or is cooking them out via the preparation process (such as making flakes or pellets versus crumbles which destroys less of the nutrition value). Admittedly even some of the better brands perform supplementation, but I still would seek a fish food that supplements as little as possible.
In fact there are many otherwise good fish foods on the market that utilize excellent ingredients (especially the newbies in the market), but their failure to optimize ingredients and/or their preparation process often leaves these fish foods lacking, this includes many, if not most, of the popular so-called "quality" fish foods currently on the market. In other words these fish foods are all about the ingredients, but miss the even more important analysis!
This is not new to the hobby either, or even to fish foods, as I have been to pet nutrition seminars where it is pointed out that the ingredients are quality, but the optimization is lacking.
Often what is pointed out in fad foods is their fish are growing and doing well, but in reality these fish are simply going through their life cycle fast, similar to Beef Cattle fed grains and high growth formulas to get them to market fast versus Cattle fed a slower but healthier growth "grass-fed" diet.
This is where Clay Neighbor's work in fish nutrition has improved on just using top notch ingredients, he (along with myself) have realized for years after many controlled tests and observations that it is not only about top quality ingredients than taking this to the "more the better" as so many fish foods have done and continue to do. Clay's latest innovation is the "AAP Custom All Natural Fish Food Crumbles" which is the most optimized prepared fish food available.
Hopefully this article can educate readers as to all important aspects of what goes into an optimum prepared fish food diet. This way readers can apply this information to any fish food in an educated manner.
As while I certainly recommend many excellent fish foods in this article (as in the previous paragraph) as well as "pan" others, there are certainly many others that are not mentioned that might be excellent based on the ingredients along with any optimization of these ingredients as well as the order of the ingredients (it is noteworthy that all ingredients are listed in order of most to least).
However the reader may also find out that what they may have considered a top notch fish food is not quite as good as they thought as per poor optimization of proteins, fiber, and especially energy levels which can cause renal failure or fatty liver disease over time.
There is a lot of confusion about what constitutes an optimal fish food.
The aquarist needs to understand that there are similarities and differences between fish and other animals.
For example; Fish get most of their energy needs from fat, however in humans carbohydrates are generally considered the better source.
Another point is amino acids (the building blocks of proteins); almost all animals have different amino acid needs.
For example; Cats need Taurine in there diet or they can suffer heart problems.
Back to fish; the wrong amino acids in any fish will lead to aquarium pollution (extra ammonia) from lack of digestibility and potential renal failure (kidney failure) in the fish.
We also know from studies in human nutrition that certain diets add to inflammation and oxidative stress. This is easily carried over to fish nutrition as well.
Examples include Omega 6 versus Omega 3. In too high of a ratio, Omega 6 will create inflammation and oxidative stress which can lower disease resistance.
Anytime one feeds fish foods with excess energy levels, this too creates oxidative stress. But unfortunately even the vast majority of so called premium brands have excess energy levels in part because they utilize ingredients that go after palatability over optimized energy levels, often with levels vastly higher than they should be.
Then there is the speed of digestion, some fish such as goldfish tend to have slower digestive tracts (I like to compare it to a horse, but there are major differences such as the stomach).
One similarity is that if too high a protein or the wrong protein diet is fed, the horse may colic, and in goldfish they will build up intestinal gas and infections including of the swim bladder or occasionally dropsy will ensue.
As for the stomach of goldfish (& other cyprinids), I would have to respectfully disagree with the TV show "Tanked", as although it is a rudimentary stomach, from what I see of the goldfish anatomy IS A stomach.
Reference: Do goldfish Have a Stomach; The Fish Vet?
But more importantly, regardless of which side you fall on the issue of whether or not a goldfish has a stomach; What is a fact is that this small or rudimentary goldfish stomach along with their long intestinal tract tends to loose moisture readily because of this small stomach and long intestinal tract.
So soaking dry goldfish foods is ESSENTIAL for prevention of bloating and gut Aeromonas infections. As well, too high a protein diet can cause issues, which is why a diet rich in slow to digest plant based material such as algae is essential (Spirulina is best), but low in certain proteins that require short intestinal tracts.
Here is a quote from a Veterinary University article:
"Goldfish use their long intestine to feed heavily on difficult-to-digest algae and organic detritus"
Back to other Fish: Another note about fish food is what carnivores need. Carnivorous fish often consume whole animals including intestinal contents, which often include plant material. A quality fish food for carnivores must include vegetable matter such as spirulina.
An important point about aquatic nutrition to think about is what is best for the fish is NOT necessarily what the fish eat most readily.
Many foods add ingredients that “enhance” flavor and use terms such as the “Rich Mix” to describe their product and claim that fish eat their fish food well, which is often true.
HOWEVER this is NOT an indicator of quality nutrition.
Think about this; when is the last time you have placed spinach and candy in front of a child and seen what one they will pick?
Or it has been shown in studies that most dogs will prefer cat food over dog food due to cat foods more “rich” ingredients, yet in these same studies dogs fed a diet of cat food are destined to an early death due to renal failure.
Along this same line, if I offer TetraMin at the same time as a superior food such as Spirulina 20 Fish Food Flake, in most instances the fish will prefer the TetraMin. However this does not prove superior nutrition in the least and in fact is the reason I generally only feed one type of fish food at a time so that fish cannot “pick and choose” what they eat and ignore a nutritional part of their diet.
This is an important point as well in the fact that many quality fish foods such as the before mentioned Spirulina Flake or Aqua Master ultra premium fish foods do NOT have added enhancers (why add these and lower nutritional value) and thus often take longer for fish to accept when first offered, but in the end I have found that well over 90% of fish will eventually accept these fish foods when that is all that is offered.
Another common practice is to artificially add colors that add no nutritional value (and may even be detrimental) just to look “pretty” or appealing to the aquarist. Some brands of Fish Food Flakes such Aqueon Fish Foods have colors of their fish foods that are attributed to the actual ingredients in the formula (such as Marigold Powder, Chili Powder, Spinach, etc.).
This method is preferable as it helps to bring out the natural colors in your fish, while keeping them energetic and healthy.
An amino acid is any molecule that contains both Amines and Carboxylic acids.
*Amines are organic compounds that contain nitrogen as the key atom; structurally amines resemble ammonia.
*Carboxylic acids are organic acids characterized by the presence of a carboxyl group.
Amino acids are used as the basic components of proteins.
The net protein utilization is profoundly affected by the limiting amino acid content or protein quality (the essential amino acid found in the smallest quantity in the foodstuff), and somewhat affected by salvage of essential amino acids in the body.
It is therefore a good idea to mix foodstuffs that have different weaknesses in their essential amino acid distributions. This limits the loss of nitrogen through deamination and increases overall net protein utilization.
Another practice often used by aquaculture, and even among many of the "better" brands is too much protein/amino acids, as this can cause kidney issues later on and affect fish longevity. Therefore the best fish foods will also blend ingredients to "limit" proteins for optimal protein/amino acid utilization.
In a study many years back where I attended a seminar, it was shown in animals that over abundance of proteins in prepared animal foods to encourage growth or simply under the assumption "the more the better" was THE cause of premature renal failure and death. This is where Paradigm Fish Foods and even more so the newer Custom AAP version formulated by Clay Neighbors is superior to all other fish foods to date.
*AAP Custom/Paradigm Ultra Premium Fish Food Crumbles
DL-methionine is an essential amino acid for producing the “Lionhead” feature in goldfish. It is noteworthy that Methionine is one of eight essential amino acids.
High levels of DL-methionine can be found in eggs, whole fish meal (in particular Menhaden found in Paradigm/AAP Custom), and in many cereal grains such as whole unbleached wheat flour, which is used in many commercial foods such as Sanyu Koi and Goldfish Food or the premium Aqua Master Fish Foods (which is high in whole fish meal, another source of methionine).
Eggs (whether fish or even chicken) has one of the higher protein qualities. Which makes hard boiled egg crumbles an excellent food source for fry.
Other essential Amino acids include (essential, meaning amino acids that cannot be produced within the fish’ body from other nutrients and proteins): Arginine, Histidine, Isoleucine, Leucine, Lysine, Methionine + Cystine3, Phenylalanine + Tryosine4, Threonine, Tryptophan, and Valine.
Other quality sources of usable amino acids include: Whole fish meal (Whole Menhaden & salmon is best), Cylcops, fish roe, squid meal, and even spirulina algae.
Bottom line; Not all protein sources are equal nor is maximum protein desirable.
An analogy used at a pet food seminar I attended was this: You can achieve the protein analysis on many pet foods with a used pair of leather shoes, but leather shoes contain little usable proteins. In this seminar the leaders demonstrated that either too much protein (instead of optimum protein) and/or less digestible proteins/amino acids led to premature kidney (renal) failure. This was easily demonstrated with Purina Dog and fish chows.
We need to remember that protein's primary function is to build or repair muscle and tissue. Its the only component in food that can build or repair muscle and tissue. Protein not used for repairing muscle and tissue can be converted to glycogen and stored. However the conversion is not very efficient often resulting in a shortened lifespan. The use of Protein as a fuel has long ago been discredited and debating protein levels at this point in time is the equivalent of debating whether the earth is round or flat.
Another point as to grain or plant sources (Spirulina does NOT fall into this category), is that proteins in cereal grains and other plant concentrates do not contain complete amino acid profiles and usually are deficient in the essential amino acids lysine and methionine.
Molecular compounds that are generally soluble in organic solvents and largely insoluble in water. Fats are important for insulating body organs against shock, maintaining body temperature, and promoting healthy cell function. They also serve as energy stores for the body. Fats are broken down in the body to release glycerol and free fatty acids. The glycerol can be converted to glucose by the liver and thus used as a source of energy.
The fatty acids are the main source of energy in fish, especially for many tissues, such as heart and skeletal muscle. Another important function for fats are for vitamin absorption.
Vitamins A, D, E, and K are fat-soluble, meaning they can only be digested, absorbed, and transported in conjunction with fats.
More information about this below carbohydrates section, including an important discussion as per energy levels ina fish food and their effect on potential fatty liver disease.
The lipids (fats) in fish can be separated into liquid fish oils and solid fats.
This is why fats/lipid for use in fish food are best obtained from aquatic sources such as Whole Fishmeal.
Fish lipids are highly digestible by all species of fish (& animals) and are excellent sources of the essential polyunsaturated fatty acids (PUFA) in both the omega-3 and omega-6 families of fatty acids.
The predominant omega-3 fatty acids in fishmeal and fish oil are linolenic acid, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA).
Both DHA and EPA fatty acids are produced and passed along the food chain by small-size algae and zooplankton, which are consumed by fish. Fishmeal and oil contain more omega-3, than omega-6 fatty acids, although not all sources are equal. Whole fish meal, in particular whole Menhaden fish meal is your best source.
In contrast, most plant lipids contain higher concentrations of omega-6 fatty acids. For example, oil extracted from soybeans, corn, or cottonseed is rich in linoleic acid, an omega-6 fatty acid.
Some oils, like those from canola and flax seeds contain linolenic acid (of the omega-3 family), however, its conversion into essential DHA and EPA by most animals may be limited.
More about Omega 3 & 6
As with most animals, it is important to maintain an appropriate balance of omega-3 and omega-6 in the diet, as these two substances work together to promote health. However in fish it is the Omega 3 that is most needed and many warm water freshwater do not readily produce this fatty acid like most coldwater marine fish can.
Omega-3 fatty acids are THE essential fatty acid and one of the benefits is that they help reduce inflammation, while most omega-6 fatty acids tend to promote inflammation.
One problem with many fish foods that are void of Whole Fish Meal (vs. plain fish meal which has often lost most oils), Fish oils, or similar are that they often will get their fats from plant sources that lack even short-chain Omega 3 and only contain Omega 6.
Very few plants produce Omega-3 fats, and plant-based Omega-3 fats such as Flax, walnuts and camelina are slightly different than fish omega-3s.
Plants produce a shorter chain molecule than fish, while fish produce long-chain omega-3 oil, but even warm water freshwater fish may be able to convert these short-chain omega-3 oils to the long-chain version.
An ongoing study has shown where farmed fish were fed partially with camelina suggested that they were converting the oil to the longer chain Omega 3 fatty acid.
Molecular substances which include the sugars, starches, gums and celluloses. The common attributes of carbohydrates are that they contain only the elements carbon, hydrogen and oxygen, and that their combustion will yield carbon dioxide plus one or more molecules of water.
Most of the carbohydrates, which enter the diet of fish are of plant origin.
Carnivorous fish such as groupers, therefore, deal with little carbohydrate. Indeed, experiments have shown that these species are ill-equipped to handle significant quantities of raw carbohydrate, in their diets.
The ability of fish to digest carbohydrates depends on their ability to elaborate amylase. All species of fish have been shown to secrete at least some amylase. It has also been demonstrated that activity of this enzyme was greatest in herbivores.
Carbohydrates are not a superior energy source for fish over protein or fat although digestible carbohydrates do spare protein for tissue building. Also, unlike in mammals, glycogen is not a significant storage depot of energy in fish.
The more efficient metabolism of amino acids over carbohydrates (glucose) by fish for energy could be due to the ability of fish to excrete nitrogenous waste as ammonia from their gills without the high cost of energy in converting the waste to urea.
ENERGY; Limiting of Fish Food Energy Levels:
What is also noteworthy is that fish use sugar and carbs/starch found in any fish food first since they can store very little if any.
In a study conducted by fish food guru Clay Neighbors (utilizing a University of Florida study as his foundation), founder of Paradigm Fish Foods & now patent pending AAP Custom Fish Foods found that fish stopped breeding after being fed a trial diets of less than 226 points (energy point system) of carbs and fats. This means that the females didn't have enough reserve energy to produce eggs. Clay raised the energy a little and the fish started breeding again.
They established that the optimum combined carbs and fat is about 280 points for the average warm water fish (in particular cichlids), anymore and the fish can suffer from fatty liver and other issues and much less and the fish are not receiving the proper energy requirements.
It is noteworthy that these same studies showed that cool water species, in particular trout, did require higher energy levels, which was to be expected.
A University of Florida study has shown ceroidosis of the organs and Malawi Bloat are directly related to energy levels of food being too high.
Another point as to the importance of optimized energy levels are free radicals/oxidative stress.
Free radicals are highly unstable molecules that are naturally formed when the fish converts food into energy. Free radicals can cause "oxidative stress," a process that can trigger cell damage, therefore limiting these free radicals by an optimized energy level will benefit your fish long term.
My own observations over decades of professional fish keeping with 1000s of clients aquariums concur with this research and also includes Dropsy and as well as issues of bloat in goldfish.
Susceptibility to other infections such as my observations with Columnaris are also confirmed in this research.
This is why the optimization of energy levels in a fish food is so important as research and professional observations point out!!
HOWEVER, My own extensive studies, in particular those I conducted using the Bahooka Restaurant's 110 aquariums showed that no one food should be used and that supplementation is always a good idea.
As well there may be times to temporarily increase energy levels such as breeding, healing after injury/sickness, etc.
As well, while I stand by the energy levels in this research, my own personal research indicates hitting this "perfect" score (280) then adding 5-10% would add any margin needed for times when energy levels might need to be quickly increased will the while not adding to fatty liver and oxidative stress more than needed.
Energy Point System
Starch, Sugar, & Proteins 1%:4 points (multiply percentage by 4)
Fats (Much more efficient energy) 1%:9 points (multiply percentage by 9).
Then add both numbers to get your fish food's energy points.
Please note many fish foods fail to provide starch/carbohydrates/sugar in their analysis, so you have deduce the carbs/sugars by adding all known percentages then subtracting to get the car/sugar likely percentage. If Ash is also not listed, I would add an average of 9% when making this deduction.
You can then add these numbers to get the points of the fish food you are feeding (this applies to dried fish foods).
The SUMMARY section of this article provides another example on how to read a fish food label using a popular discount store brand fish food so as to get these numbers. You will be astonished as to how many popular fish food brands, even those considered among the best, get poor grades as per optimum energy levels.
As an example, using a good food, but still too high in energy levels as proven in University level studies, is Hikari Goldfish Gold which gets most of its energy from starches (which is not the best way as shown), but more importantly their energy levels are higher than what are considered best. This said, I have used Hikari Goldfish Gold in extensive fish food studies (in particular using the 110 aquariums at the Bahooka Restaurant), with better results than many fish foods, but part of this reason is I used it on conjunction with other fish foods such as FD or Frozen Brine Shrimp and Spirulina 20.
So I am not saying to throw away these foods based on energy levels alone, just to only consider them a part or supplement to your fish' diet.
Further Reference: ufl.edu; "Nutrition for juvenile African cichlids"
Product Resource: Clay Neighbor's AAP Ultra Premium Custom Fish Foods
Soluble fiber attracts water and turns to gel during digestion. This slows digestion. Soluble fiber is found in oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables. It is also found in psyllium, a common fiber supplement.
Green peas contain 34% Fiber. Of that percentage 25% is Soluble Fiber.
Fiber acts as a laxative. All fiber is passed. However it has no effect on the ecology of your aquarium.
This is important in prevention and treatment of prolapse in fish.
MORE IMPORTANTLY, it has been proven that bacteria feed on the digestible portion soluble fiber (which is about 10%). According to fish food guru Clay Neighbors, this bacteria is what breaks down food sources in the digestive system of fish, much more effectively than pro-biotics would.
Since this is a small percentage of an aspect that most fish foods are already low on, the results is poor bacterial aid to digestion with the vast majority of fish foods, including what many consider to be the premium brands such as NorthFin
With the previous paragraph in mind, some would have you believe that 12% Fiber is too much for Carnivorous fish. This is simply not the case and fish food guru Clay Neighbor's research into fish nutrition using live subjects proves it.
In fact fiber numbers closer to 18-19% are much more healthy, even for Carnivores!
Unfortunately the majority of fish foods are too low in fiber, many as low as 4% or less (such as New Life Spectrum or 5% for NorthFin).
High quality whole fishmeal provides a balanced amount of all essential amino acids, phospholipids, and fatty acids for optimum development, growth, and reproduction, especially of larvae and brood stock.
The nutrients in fishmeal (such as Omega 3 fatty acids) also aid in disease resistance by boosting and helping to maintain a healthy functional immune system.
Two basic types of fish meal are produced;
(1) Fish Meal from left over parts:
Produced from fishery waste (salmon, tuna, etc.) that are associated with the processing of various edible human fishery products and this fishmeal is rendered from fish offal, trimmings or cuttings, and other wastes principally from filleting and canning operations from the edible fisheries (e.g., tuna, cod, haddock, hake, pollock).
In addition to being a by-product of human fish production it is also a by-product associated with Omega 3 fish oil production, which is where many commercial fish foods obtain fish meal from, thus loosing an important natural nutrient; Fish Oil (with Omaga 3).
Unfortunately many if not MOST of the major fish food brands use this poor source of nutrition rather than the vastly superior whole fish meal.
(2) Whole Fishmeal:
When specific fish (Herring, Menhaden, Anchovies, Hakes, Jacks, Pollack, etc.) are harvested just for the purpose to produce fish meal. The fish can be dried directly drying or cooking prior to drying and oil extracted.
Most of these fish are small, bony, with high content of oil (especially the important Omega 3 discussed in the “Fats” section), and considered of little edible use for humans (e.g., anchovies, herrings, capelin, menhaden).
Fish that are only used for the production of fish meal are the best source, listed on ingredients as “Whole Fish Meal”, “White Fish Meal”, or the best: “Whole Menhaden Fish Meal” (found in AAP/Paradigm fish foods).
Fishmeal of high quality provides a balanced amount of all essential amino acids, phospholipids, and fatty acids (Omega 3, DHA or docosahexaenoic acid and EPA or eicosapentaenoic acid) for optimum development, growth, and reproduction, especially of larvae and brood stock.
The nutrients in whole fishmeal also aid in disease resistance by boosting and helping to maintain a healthy functional immune system.
Most plant-based proteins, even when properly processed (with the exception of Spirulina, which is not actually a plant or even a true algae), are usually not as digestible as fishmeal; and their inclusion rate into the diet is often limited as it results in depressed growth rates and feed intake.
Over-all protein digestibility values for premium fishmeals are consistently above 92%.
In comparison protein digestibility for many plant-based proteins varies greatly, for example, from 77% to 96%, depending on the species of plant.
Whole Fish Meal is an excellent source of DL-methionine which along with some fats such as the VERY important Omega 3 fatty acid is important to large head growth in certain cichlids and Orandas/Lionhead goldfish.
As noted earlier, unfortunately many leading brands of fish food use only bi-products or low quality Fish Meal which is not complete.
Whole Fish Meal averages between 17% and 25% ash content.
More ash indicates a higher mineral content, especially calcium, phosphorus, and magnesium. Calcium and phosphorus constitute the majority of the ash found in fishmeal.
This makes Whole Fishmeal an important source of very essential minerals that fish need for osmoregulation.
Reference: Aquarium Answers, Osmotic Regulation in Fish
Fishmeal also contains certain compounds that make the fish food more acceptable and agreeable to the taste (palatable). This property allows for the feed to be ingested rapidly, and will reduce nutrient leaching. It is thought the non-essential amino acid glutamic acid is one of the compounds that imparts to fishmeal its palatability.
Use of high quality fish meal as a percentage of processed/prepared foods ranges from 5-7% for koi and goldfish, and up to 40% to 55% for high protein tropical fish, trout, salmon, and some marine fishes diets.
Unfortunately the cost of high-quality whole fishmeal (65% protein) is 2.0 to 3.5 times the price of soybean meal so its use is often low as compared to soybean meal or lower quality fishmeal in low end fish foods (which make up the more popular brands too).
Further reading for Fish Meal (resource)
Fish Meal in Aquaculture Diets; University of Florida
Recommended Product Resource with Whole Menhaden Fish Meal:
*Clay Neighbor's AAP Custom, Fish Food Crumbles with Whole Menhaden Fish Meal
"Condensed Fish Protein Digest" is the condensed enzymatic digest of clean undecomposed whole fish or fish cuttings using the enzyme hydrolysis process.
Reference: Enzymatic hydrolysis; Wikipedia.
This product can better be defined and is often labeled as "fish protein hydrolysate". This hydrolization process involves the liquification of whole fish or fish left-overs in a vat of enzymes. The bones and scales are discarded with the subsequent slurry passed through a spray dryer. The end product that is often used in fish foods is an inexpensive, highly digestible protein that is practically void of ash and phosphate.
While there are both positives and negatives of the use of this product in fish foods, the negatives clearly outweigh the positives.
The positive is a cheap source to drive up fish food protein numbers and keeps phosphates to a minimum.
The negative is it is better to bring up protein numbers by whole complete ingredients. As well, this process removes essential natural minerals that are important for the fish, including osmoregulation.
Since most "Condensed Fish Protein Digests" are made from fish "left-overs", similar to the use of standard fish meal most fish foods use versus whole fish meal, we are further diluting the natural nutritional value of a fish food.
Ocean Nutrition is a popular fish food that unfortunately uses this product.
Shrimp meal can be made from either cull shrimp that are being processed before freezing or from whole shrimp that is not of suitable quality for human consumption. For fish food, in most every instance for fish food it is only shrimp "parts" with just 20% digestibility that is used
The material to be made into shrimp meal is dried (sun or using a dryer) and then ground. Shrimp meal has been used in trout and salmon diets as a source of pigments to impart the desirable color in the tissues.
A positive aspect of Shrimp or Krill Meal is that it often has a high palatability for many fish, especially small “finicky” fish such as many small Tetras.
For this reason many fish foods specifically designed for small finicky fish includes this food source as a major ingredient.
Examples include 'Hikari Micro Wafers' (which also includes Garlic) or for delicate Marine Fish, 'Hikari Marine S'.
Both Shrimp or Krill meal has been found to be an acceptable supplemental protein source for fish, but inferior to whole fish meal such as Whole Menhaden Fish Meal for pepsin digestibility.
As well, over all protein digestibility of the Shrimp meal in particular used for fish foods is low compared again to other protein sources such as Whole Menhaden Fish Meal with Shrimp coming in at about 20% digestibility while Whole Menhaden is closer to 90%.
Another issue with shrimp meal and especially Krill meal is its over all energy levels are too high which long term could lead to fatty liver issues.
In the end, both Shrimp and Krill meals are a great appetite stimulant and part of a diet if fish are finicky eaters, but if the fish will eat other foods just fine, shrimp/krill or fish foods containing krill/shrimp should be avoided long term!
Squid Meal is made from squid viscera portions from cannery plants including egg and testis.
Squid Meal is high digestibility of protein source, which provides a full range of amino acids for fish. It provides various kinds of vitamins and minerals and also 1.0-1.5% of cholesterol that is suitable for fish fry and young fish.
Just over a centimeter in size, the adult brine shrimp (Artemia) is a common food source for fish. They can be purchased at many Pet Stores as adults, Freeze dried or even eggs.
The eggs look like a powdery brown substance but in reality the substance is thousands of cysts—eggs surrounded by protective cases. When added to water, these cysts will hatch into shrimp nauplii within a few hours.
As I noted, Brine Shrimp have a natural laxative ability and along with shelled peas makes for an excellent laxative for constipated fish.
Even better would be to combine a high content Spirulina Flake such as Spirulina 20 and make a thick soup and soak some frozen or even FD Brine Shrimp (frozen or live is slightly better) for a natural immune boosting/laxative that is excellent for Bettas, goldfish, etc.
Hikari also makes a Spirulina enhanced FD Brine Shrimp product that is excellent as well.
Spirulina is a blue-green plant plankton rich in raw protein and seven major vitamins: A1, B1, B2, B6, B12, C and E.
Spirulina naturally contains beta-carotene color enhancing pigments (1500 mg/kg. Carotenoids; Orange/ Red pigment enhancers), and whole range of minerals.
In addition, it contains all essential fatty acids and eight amino acids required for complete nutrition.
Spirulina is different from other algae and is similar to bacteria in many ways, occupying a niche between plants and bacteria.
Spirulina is similar to cyanobacteria in structure which can be toxic (spiral shape, unlike true plant plankton).
Spirulina and Blue-Green algae are recognized by the body (fish in particular) as a bacterium, causing an increase in antibodies, which in turn increase disease resistance. Spirulina is also high in usable or digestible amino acids.
Spirulina is probably one of the best fish food ingredients available, INCLUDING for carnivores (as PART of the diet, usually fed via gut loading, more information later in the article).
Any staple fish food diet for community fish is improved by the addition of Spirulina Algae, which is why Spirulina 20 which has Spirulina as its number one ingredient is superior to most other basic fish food flakes for everyday feeding of general/community aquarium fish.
One of the negatives of Spirulina is fish sometimes have to be hungry and then acclimated to a fish food containing a high amount of Spirulina as it is not as palatable to many fish. I noted this in my fish food trials going as far back to the late 1970s using "Aquatronics Green Flake Plus" where fish when given a choice would go for much less healthy foods with enhancers for stimulating appetite over Spirulina based foods.
However, once acclimated, most fish would then readily accept Spirulina based foods and the difference in fish disease resistance, longevity and sometimes color was noteworthy over other fish foods I tested.
For much more about Spirulina as to the health benefits there in:
Spirulina Algae; The aquatic health benefits for Tropical, Marine and Goldfish.
There is a lot of both subjective and objective evidence about the use and effectiveness of garlic for fish.
Much of this is positive, but there are also negative reviews of the use of Garlic. It is also noteworthy that any heat destroys many beneficial aspects of garlic. There is also research (mostly outside of the aquarium hobby) showing that garlic use may help prevent certain pathogens from affecting one's fish, but not necessarily treating a full blown disease.
I myself have used Garlic as an appetite stimulant with good results, which use as an appetite stimulant is not controversial as it is with medicinal uses.
Based on a study ("Using Garlic as an Appetite Stimulant in Sand Tiger Sharks." Drum & Croaker, January 2004, Volume 35, pages 59-63"), I would have to venture a guess that the results that I and others have observed were real, it simply depends upon the fish and what stimulates certain fish, as this study was quite flawed and only dealt with one type of fish. My positive results were with omnivores and herbivores, but not carnivores (in particular Yellow Tangs and some livebearers I only used Garlic to stimulate appetite).
Here are a couple other claims of benefits for Garlic use:
• Anti parasite including internal worms as well as Freshwater Ich (Ichthyophthirius multifiliis) & Marine Ich (Cryptocaryon irritans).
* I do not have good evidence of the benefit of Garlic for parasite treatment, however I have found that occasional use (such as when new fish are added) that Garlic seems to lower the chance of Cryptocaryon infestations versus fish not fed garlic infused food.
This anecdotal evidence is backed up by human research into malaria (of which both single celled parasites are affected by PROVEN similar therapies such as Chloroquine Phospate and pyrimethamine).
In one such study, Ajoene, a disulfide that naturally occurs in garlic, appears to work by blocking the action of glutathione (a protein that is of particular importance in cells that rapidly reproduce such malaria-infected cells).
What this means for us fish keepers is not that garlic will necessarily treat an Ich (or Cryptocaryon) infestation, but provides some strong evidence that backs up my own anecdotal evidence that when used OCCASIONALLY (such as new fish introduction/quarantine) garlic supplements can lower the chance of such an infestation.
Reference: Garlic 'fights malaria'
* Garlic contains the active (& proven) ingredient; Allicin, (a.k.a. Diallyl thiosulfinate)). Allicin is a broad-spectrum agent against both Gram Positive and Gram Negative bacteria, with more gram positive activity (which unfortunately most aquatic diseases are gram negative).
Allicin does not readily occur in garlic, rather it is produced when garlic is finely chopped or crushed. The finer the chopping and/or the more intensive the crushing, the more allicin is generated and the stronger the medicinal effect.
This medicinal effect degrades with time and heat.
* Fish Tuberculosis (Mycobacterium marinum) has been demonstrated to be effectively treated with Allicin. Some human studies show the effectiveness of Garlic (Allicin) in treatment Streptoccocus (which can affect fish).
Reference: TB in Fish; Mycobacterium Tuberculosis
There has been some Internet myths being circulated that the use of Garlic can cause liver damage in fish.
Since the aquarium hobby/industry has very little $$ for real research, the best way to check something like this is via medical websites where there likely is more real research instead of the anecdotal and worse, often opinions with no basis of fact.
With normal use (not exaggerated doses or constant use), all I could find is problems via interaction with other medication including NSAIDS, blood thinners, & Protease inhibitors (a class of antiviral drugs).
It is highly unlikely that any aquarium hobbyist would use such drugs in their aquarium and so it is more likely the fish liver would actually benefit from the use of a short term garlic soak. Better, if concerned about liver damage in your fish; STOP feeding the vast majority of fish foods on the market with too high energy levels (which can cause fatty liver issues as cited earlier in this article).
Just as importantly since regardless of how one feels about garlic, it is quite clear it should not be used constantly, especially in high doses. While not a perfect analogy (since Vitamin A is required and garlic is not), it is noteworthy that even Vitamin A can cause liver damage at certain dosages.
Garlic Use & Liver Damage
I would caution though that raw garlic can burn through intestinal walls and kill off gut bacteria as well as cause anemia, so I would suggest on/off use.
In the end, based on research and experience, garlic is an ingredient best used occasionally for different reasons, but should not be used indefinitely nor should it be part of any prepared fish food that is the mainstay long term diet.
Garlic can be added to fish food at about 1-2% (generally during manufacture or homemade fish food) or an aquarium keeper can add professionally prepared products such as SeaChem Garlic Guard to fish food prior to feeding (a half hour or more is best to allow food to absorb the garlic).
However, adding garlic to most prepared foods prior to cooking nullifies most benefits. AAP/SeaChem Garlic Guard uses crushed garlic extracts, not heat to produce the product.
AAP/SeaChem GarlicGuard can be mixed with Metronidazole or Neomycin and then fed used as a food soak for treatment of internal bacterial and some parasites.
For Fish Tuberculosis, Garlic Guard can be mixed with both Neomycin and Kanamycin for improving the potential effectiveness of tuberculosis treatment.
*AAP Garlic Guard; Fish Food Appetite Enhancer, TB treatment
*SeaChem Neoplex (Neomycin)
Although still fed to fish and often part of many homemade fish food recipes due to popular YouTube channels and other social media, Beef Heart is a food source that should be used very sparingly if at all.
Although many carnivorous fish enjoy it and it may be a good way to kick start growth in juvenile fish, excessive long term use can add stress to the fish' digestive tract and kidneys, thus lowering resistance to disease and shortening lifespan (which I noted in some side by side fish food comparisons in the 1980s where Oscar Fish that were fed a diet primarily of Beef Heart had CLEARLY shorter life spans and were more prone to infections or other problems such as HITH).
Although lower in fats than most warm blooded animal meats, Beef Heart is still about 18% Saturated Fat. These fats are very difficult for fish to process these fats, especially older fish.
The well known aquatic author Martin A. Moe (my favorite is the
"The Marine Aquarium Handbook") states:
"Fish are cold blooded and all digestion reactions take place at 70 to 80F, the temp of aquarium water. Thus they may not be able to efficiently digest or use the types of fats present in the flesh of warm blooded animals. They are much better off with the flesh of animals that are similar to their normal prey."
As well the amino acids (which make up proteins) are not ones that are easily utilized by fish.
Another issue with the use of Beef Heart is due to its make up, it often leads to considerable aquarium pollution when used regularly, which is another reason to use sparingly (if at all).
Unfortunately our hobby seems to no longer respect mentors or those who existed even a few years before they got into hobby with their Facebook pages and YouTube channels, so the experience of Martin A. Moe & others is but a foreign language to these persons who should know better as the use of beef heart was LONG AGO discredited as a fish food source.
So BEWARE please do not make this mistake.
Use of soybean products in the aquaculture industry have become the focus of protein substitution in fish food around the world. The high protein level makes soybean meal a key ingredient for aquaculture feeds since soybean meal is considerably less expensive than traditionally used marine animal meals.
Another thought about soy is its digestibility compared to animal based proteins. I have done a lot of reading on this aspect if only because I have become a "SIBO" patient in recent years (Small Intestine Bacterial Over-growth). I have found in practical experience and then later read that soy based products cause me more issues.
While the use of soybean meal is OK, fish foods that use soybean meal as the primary protein source should be avoided. Moreover, use of soybean meal as a source of vegetable matter should also be avoided as this can affect the protein limiting when used with other protein sources such as whole fish meal.
Carbohydrates as explained earlier are not the best source of energy in fish, but sources of Carbohydrates still can be useful, especially when whole wheat is used.
Whole Wheat in your goldfish/koi diet (such as AquaMaster PremiumKoi Diet) can act to prevent intestinal distress which in turn help prevent opportunistic internal Aeromonas infections.
Gluten is a protein composite that appears in foods processed from wheat and related species.
Glutens are also the basic source of glutamate, what the Japanese call "umami" what Americans and others call savory - the flavor produced by proteins and amino acids found primarily in meat. When cooked in broth, gluten absorbs some of the surrounding liquid (including the taste) and becoming firm, making for popular meatless, inexpensive filler used by many fish foods (& human foods).
Green peas or green pea flour is a good source of fiber (when not over processed & include the hull). Pea flour is also used to lower protein which is important and missed often even by premium brand fish foods. Please reference the amino acids section earlier in this article for more.
This ingredient when dried contains 26.6% protein without a complete amino acid profile so it is NOT and should not be used as a complete diet as per proteins/amino acids. However it is a superior source of vegetable matter for fish, with one of the most complete vegetable nutritional make-ups of any vegetable sources, including kelp.
Dried green pea flour also contains these nutrition parameters: 2.4% fat/lipids and 28.2% starch, 27.7% fiber, 6.9% sugar, 3% minerals and 5% moisture.
Fresh or frozen green peas are often used as a digestive aid for constipation in fish (along with Brine Shrimp), in particular Goldfish.
Reference: Green peas nutritionBack To Top
Cricket Flour/Meal is highly digestible and since insects or insect larva/pupae are a common natural food ingredient for many fish, its use as part of carnivore or omnivore fish food is something that improves the quality of the food but is unfortunately not very commonly used (likely due to costs).
Cricket flour is a complete source of protein containing essential amino acids that include; leucine, lysine, methionine, phenylalanine, threonine, and valine.
Of course fresh or FD Crickets are an excellent food source for fish large enough to consume these food sources, especially when gut loaded with Spirulina prior to feeding (as noted later in this article).
First here are a couple of immune enhancers used in prepared (or homemade) fish foods. Spirulina could be included too, but since it was already covered separately, please refer to that section of the article.
*Paprika has anti-inflammatory properties and gives a boost to the immune system.
It is noteworthy that drying of prepared fish foods reduces Vitamin C to almost nothing however drying Paprika actually increases the Vitamin C.
*Cayenne Pepper has anti-bacterial properties and aids in digestion.
Next here are some proven color enhancers.
*Carotenoids are a broad group of terpenoid (with 8 isoprene units) color enhancers are organic pigments that are naturally occurring in the chloroplasts and chromoplasts of plants and some other photosynthetic organisms such as algae, a few bacteria, and a few types of fungus.
The following are essentially sub groups of Carotenoids:
*Zeaxanthin is a carotenoid alcohol that is considered by Koi experts in Japan to provide vivid color-enhancement of the yellow, orange, & red areas ('Hiban' as per Japanese Koi breeders), all the while not impacting the white areas ("Shiroji" as per Japanese Koi breeders).
Zeaxanthin is found in Paprika, Safron, marigold, and most notably Spirulina.
*Astaxanthin is a carotenoid belonging to a class of phytochemicals known as terpenes that is helpful for enhancing red pigments.
Astaxanthin is found in Chlorella algae, lobster, salmon, trout, krill, shrimp, crayfish, crustaceans, & other shellfish.
Most of the astaxanthin for aquaculture is produced synthetically even though astaxanthin is fairly abundant and obtainable from natural sources (albeit for triple the price).
Here are a few other color enhancers and their color enhancing abilities (although not all scientifically confirmed)
*Lettuce; this is mostly cellulose and empty nutrition and worse lettuce is an excellent breeding ground for bacteria that can in turn cloud your aquarium and compete with fish for oxygen (many labs use lettuce for this).
*Bread; again mostly empty nutrition to fish (maybe not for humans, but as noted earlier fish get their energy primarily from fats). Also bread again will attract un wanted bacteria.
HOMEMADE FISH FOOD:
You can make your own supplement for general fish feeding that is high in DL-methionine; Start with whole salmon which is an excellent source of carotene for color (frozen or even canned works), frozen peas, hard boiled egg, frozen or FD brine shrimp, duck weed or spiulina powder, and fish oil (cod liver oil works fine). Blend this mixture then add corn starch to the paste to dehydrate. Spread this paste on small strips of foil (or even wax paper if your dehydrator does not get too hot). Make sure you leave room for air circulation.
*For a frozen food, substitute the corn starch with unflavored gelatin powder.
*For cichlids, goldfish and koi, add wheat germ powder.
*For more carnivorous fish increase the whole fish and decrease the spirulina powder or duckweed. Calamari (squid) can be added too for carnivorous fish, but make sure that all the ink is removed from whole squid.
* For better attraction (smell) as well as a parasite repellent (Ich), you can add garlic powder to each batch of frozen or dried fish food at a rate of less than 1% of the prepared batch, this comes to about ½ teaspoon (or less) per one cup batch of wet fish food (before drying/freezing)
For spirulina powder, Spirulina 20 Flake can be substituted, but since this already a complete diet for many fish, I double the amount of this and decrease other ingredients by comparable amounts.
Here are basic percentages, please note that you can change these percentages to suit your fish food requirements:
Some suggest the use of Agar as a binder in place of Geletin, however I do not recommend this based on evidence, while not fully proven, that Agar allows Saprolegnia to gain a foothold in an aquarium and that Agar can allow Heterotrophic bacteria to crowd out the needed Autotrophic bacteria for a healthy aquarium nitrogen cycle.
LIVE, FROZEN OR FD FOODS:
As stated earlier, this article has been primarily about prepared foods; however this is not to say that this is all you should feed, far from it. Many fish benefit from live, frozen or freeze dried supplements such as Brine Shrimp, Blood worms, Daphnia, Microworms, Whiteworms, Walter Worms and more. Make sure that you make sure that live foods come from an uncontaminated source and some foods such as Tubiflex Worms are raised in polluted waters which make them a poor choice.
Worms & Brine Shrimp
For young fry such as Bettas; Walter Worms, newly hatched brine shrimp, vinegar eels or Micro Worms are an excellent choice (Micro Worms tend to drop to the bottom and Vinegar Eels may be a good alternative).
Reference: Worms used as Fish Food; Aquarium Answers
Here is place to purchase Grindal Worms, Walter Worms, or Vinegar Eel starter cultures:
Over a Copper Moon; Live foods
Here is a little about Micro Worms:
Micro Worms are nematodes (Panagrellus).
Microworms are one of the easiest live foods to culture.
Micro Worms are small .5 -1.5 mm and difficult to see individually. They are white, un-segmented worms that move continuously. The tail end is pointed while the mouth end is generally more rounded. They are approximately 15 times as long as they are wide.
Due to their size and shape, they can be fed to fish that are too small to take a brine shrimp nauplii.
Microworms can remain alive in fresh water for twelve hours or more.
Microworms reproduce sexually. The males have a curved tail, are smaller, more slender, and lower in number than the females.
Micro Worms are live bearing, producing 10 to 40 young every 1 to 1.5 days for an average 20 to 25 day life span. This results in each female producing approximately 300 offspring. The young reach sexual maturity in approximately three days.
Their size increases by three times during the first day and five to six times during the next three days. The Micro worm nematodes are 76% water and 24% dry matter; 40% of the dry matter is protein and 20% is fat.
Micro Worms are easily cultured, here is a link to a starter culture:
Live Microworm culture
A simple mix is one cup of quick oats, baby cereal, Cream of Wheat or similar (with maybe a tiny pinch of dry yeast) to one and a quarter cups of warm water.
Mix thoroughly and pour into a suitable container. Yogurt containers or similar types of containers work well for culturing Micro Worms.
Allow cooling, and then seed the mix with worms, putting the lid on (with small holes for ventilation) and leaving in a cool place. The temperature should be between 65 to 75 degrees.
Within a few days you will have Microworms to harvest.
For MORE information about worms for feeding as well as many more resources (including links from which to purchase), please see this Aquarium Answers Article (near the bottom):
"Trematodes, Nematodes, Annelids, & Feeding Worms"
HOW AND WHEN TO FEED FISH
No one fish food should be relied on as your fish’ sole nutritional source.
For problems with intestinal distress in fish (very common with goldfish, however Bettas and many other fish can suffer too), you fist want to avoid this by feeding foods with the best ingredients (as noted earlier in this article) and keeping your fish in water with the Proper Electrolyte levels.
POOR APPETITE, MALNUTRITION, SICK FISH:
Often new fish will not eat (more common with carnivores in my experience, especially those that are being adapted to a prepared diet such as Bettas).
With some carnivores, the answer may be as simple as “gut loading” their food as discussed earlier (even live worms can be fed Spirulina or similar prior to feeding), however often the answer to the problem is not as simple.
In these cases preparing a fish food soaking slurry (or thick soup) is the answer.
This slurry is NOT an exact science, but it has been effective for me, and as well for internal diseases or parasites (such as the often common intestinal flagellates found in many wild caught fish such as Clown Loaches, wild Discus, etc.).
When I use medications in the slurry, I generally add medications at a 10 gallon tank strength per batch (please note that I do not use medications in all food slurries).
For this Slurry, I prefer to use (1) tablespoon Spirulina Flakes, a human multi-vitamin (capsules that contain a liquid work best, however any can be ground up, as well make sure there are NO added sugars, colors, flavors, etc., only pure multi-vitamins), minerals (scrapings from Wonder Shells are what I have used since they are balanced), and Omega 3 fatty acids from a human capsule that is poured into this slurry.
Generally for one tablespoon of Slurry I will use half of the average Omega 3 capsule (about the same for the multi vitamin along with just a few scrapes of a Wonder Shells or similar). I mix this to the consistency of a VERY thick soup and then soak the Brine Shrimp, pellets, etc. for about ½ hour in this.
PROBIOTICS FOR FISH:
First I will explain what a probiotic is:
The use of probiotics whether homemade or commercial is best performed immediately after use of antibiotics on your fish either or both "in tank" or in baths.
There are many commercially available probiotics for fish, however the shelf life is often questionable.
However making you own probiotic is not difficult at all; simply using a plain yogurt with no sugar or other additives can work.
This can also be used to feed feeder fish, worms, or any live food fed to carnivores immediately prior to the feeding of these live foods to their intended carnivore fish.
BEST USED BY DATES:
This is sometimes controversial, but ONLY due to miss-informed persons who do not realize that Fish Foods are NOT required to place such dates on their fish foods and/or do not understand what this means or what even the laws are about this mythical date.
Hopefully the reader has gained some very helpful insights into what truly constitutes an optimum fish food. As I noted in the beginning, my fish food trials starting at the Bahooka Restaurant in the 1970s in their 110+ aquariums under contract were my earliest tests.
Keep in mind certain specifics about the fish you keep.
Learn to read a fish food label, as most fish food labels leave off the full picture, thus leaving the fish keeper guessing.
I should however point out that there may be a time for slightly higher energy levels (not the crazy high energy levels of so many such as NLS) for juveniles or even adult fish that need to repair tissue.
Finally, be careful of fish foods that are often sold by discounters that make a generic formula and markets them to all types of fish with slight variations (if at all in some cases). This is unfortunately a common practice.
In the end, the information given in this article should also help you to make a better choice when purchasing prepared fish food (especially when feeding young fish!), such as the examples below:
When it comes to feeding young fish (fry), a quality prepared food is even more important. A comparison I would use is this; would you feed your infant cows milk instead of formula?
Spirulina, ground whole wheat, whole fish meal, defatted soy meal, wheat flour, torula dried yeast, vital wheat gluten, fish oil, biophos, soy oil, lecithin, natural colors.
Product Resource: ZooMed Spiulina 20 Fish Food
As you can see, both are excellent formulas, although different in their nutrition approach (they can be used together).
SOME FISH FOOD REVIEWS(With input from Everything Aquatic & Trusted Aquarium Maintenance Companies), far from an exhaustive list too.
This list is intended as a list of fish foods intended for daily basic feeding, not as the only food to feed.
Resources (references), further reading
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