POND CARE INFORMATION; From Filters to Maintenance for a "A Clear Pond"
By Carl Strohmeyer-PAMR 35+ years experience
 ADEQUATE WATER CIRCULATION AND MOVEMENT (Pumps).
A general principle (not a rule) of about 50-200 gph per 100 gallons can work for this (A lower proportional gph for large ponds, a higher proportional gph for small ponds). This can be achieved with more than one water pump.
Pump Protection from Debris
For further protection, you can place your pump in a DIY bucket (or box, etc.) pre-filter, or simply cover the pump with 1/2" to 1" rocks (porous lava rock is best).
For small to medium ponds (100–800 gallons): the SunSun HQB Series Pumps, or Rio 1700 all are proven in professional pond maintenance to be efficient and reliable, as well as reasonably economical pumps (the Rio 1700 has an available water Fountain Kit).
For even more head pressure for high pond features (such as a water fall or spitter) that require lifts of much more than 6 feet the Rio HF Water Pump line is without comparison with their Vortex Rotor Blade (which can lift up to 14 feet), especially for the price.
Using PVC 'T' Diverters also allows for the use of these large pumps for smaller ponds under 1000 gallons where multiple features and/or high head pressure features are being run.
Sometimes flexible/vinyl tubing will be difficult to connect, however by lubricating the connection, then heating the tubing, along with clamping with a standard hose clamp in some instances, this should not be a problem. This works for clear, black and ribbed tubing.
 GOOD FILTRATION.
Aquarium and Pond Nitrogen Cycle
Multiple types of filtration in combination are also excellent, such as these to name a few:
Readers might note that I did not include skimmers in my list above. While popular, I personally do not care for pond skimmers as these often tend to trap water lilies, hyacinth, and other floating pond plants all the while providing little to the quality of pond filtration (other than removal of floating leaf debris, especially in autumn).
I have found when I took over a pond care contract for a client that already have a skimmer, I would later disconnect the skimmer after adding a Veggie Filter. Part of the problem is many of the ponds I was called to consult on "after they were built" were built by "pool guys" and skimmers are great for pools, but not ponds and these builders often knew little to nothing about building a living pond, including a bog/veggie filter.
In the end, the pond actually was MORE clear with more natural looking floating plants too!
So avoid the sales pitch by many, do NOT purchase a pond skimmer by ANY maker!
The picture to the above shows a Via Aqua Multi-Purpose Pond Pump embedded in loose volcanic rock (for added pre-filtration as noted earlier) connected to a Pressurized Pond Filter and then to a High Output Pond UV Sterilizer/Clarifier.
This picture displays how a large pump (as shown with the high flow VA Pump) can be utilized for more than one function, including multistage filtration, UV Sterilization, a fountain and even can be diverted for watering a Veggie Filter.
Please note that a control valve may be needed on both sides of the diversion ‘T’, otherwise the water will follow the “path of least resistance”, put another way if your water flow is too slow through the UV Sterilizer/Filter side of this example, it may be that the return is too high above the other return and simply lowering the return will solve this problem. As well after splitting a return line, the lines should not be combined later in the return. Please read the UV Sterilizations section for more on this subject.
*SunSun Premium Pressurized Pond Filter with UV
*TMC Pond Advantage Premium VERY High Output UVC Sterilizer
In fact Pond Matrix provides the best internal macroporous surface area of ANY product and is an excellent compliment to a pressurized filter, waterfall filter, drum, or large sand/bead filters such as the AquaBead.
I prefer pressurized pond filters such as the SunSun UVC Pressurized or others for their efficiency and ease of hiding in the ground.
For small ponds and patio ponds (ponds built in above ground "Rubber Made" or other similar containers such as converted horse waterers), large sponge filters are excellent bio filters and reasonable mechanical filters. They are inexpensive, easy to service, and simple to attach with either a power head pump or and air stone.
A top notch (& unique) filter for ponds up to 500 gallons would be a TMC V2 1500 Fluidized Filter when combined to a pre-filter system as pictured to the left.
Medium Pond (250-2000 gallons depending upon fish stocking and natural debris fallout);
Bio falls such as the Savio Livingponds Filters are also excellent pond filters for medium and many larger ponds.
Plastic grates and even rocks formed into basin can be used to construct the bio and mechanical filter for flow through either prior to a water all or after (prior is more common). If a cement product is used in construction, I recommend sealing it with a water proof sealer available at most Home Improvement Stores.
*As noted earlier, Pressurized Pond Filters are an excellent choice for medium ponds. These can used with other filters for improved filtration and redundancy or even larger yet ponds.
*A filter that is also used is pool style sand filters. I have used these filters in many of my largest pond installations (over 5,000 gallons).
The Nexus Moving Bed Filter or TMC Pro Pond Fluidized Filters are a potential consideration for large ponds as their design lends itself better especially to ponds over 2500 gallons.
Volcanic rock makes an excellent filter media for DIY pond filters, waterfall filters, veggie filters (for the base), and many types of commercial filters such as the Savio.
 PLANT FILTRATION (Often called Veggie or Bog Filters);
I will often place this plant/bog filter in an area of water constriction between two ponds or in an upper waterfall area with low to moderate current. In smaller Ponds I will just place this plant filter in a corner of the pond with a small water current applied to the planted area.
Here is a video showing how the proper construction of an "in-pond" Bog/Veggie Filter coupled with a TRUE UV Sterilizer (in this case the TMC Pond Advantage, do not use an economy UV) can make a big difference in just a couple of days:
FOR MY FULL VEGGIE FILTER ARTICLE, please visit this link:
This article includes much more information on this subject, as well as links to resources for bog plants and similar.
The bottom line is few ponds in my opinion are truly complete without a "Veggie/Bog Plant Filter" as they can make a big difference when done right in pond clarity.
As an example, I had one pond I built for a client that had such a large and efficient Veggie Filter that it stayed clear without the UV Sterilizer running.
For those who read this, please note that my emphasis of the use of Veggie filters is not driven by financial gain, as although I obviously list products to sell through my many articles (as a means to pay for the time to keep these articles up to date), I have little to gain since Veggie Filters are primarily a DIY products.
The picture above/right is of a pond with relatively new Veggie/Bog filter where water flow was also recently added improving the results.
 UV STERILIZATION (& Algae Control):
Although not always necessary in a well planted, well shaded, well filtered aquarium; these devices are still very useful.
The time it takes to clear a green pond with a UV Sterilizer/Clarifier can vary greatly from 1 day to a couple weeks to even never!
The reason for such wide variance is due to lack of adequate filtration which includes a good bio filter such as a veggie filter or use of de-nitrifying products such as SeaChem Matrix or Volcanic Rock.
It is also noteworthy that the same UV or even a lessor UV may clear a pond one season and not the next; this is quite common as a pond matures, in particular in a pond with inadequate filtration!
Another common mistake is to simply run even an effective true UV such as the TMC Advantage or Emperor from just a water pump with no pre-filtration prior to entering the UV Sterilizer. This increases water turbidity considerably and thus lowers UVC effectiveness also considerably. Simply placing your water pump in a bed of volcanic rock can often work as a pre-filter, so can a Hydro Pond Sponge Pre-Filter.
Further Reference: UV Sterilization; Water Turbidity
As well longer periods or never clarifying can simply be due to an inadequate UV and/or one that is properly plumbed.
It is also noteworthy than many so called UV Sterilizers are in fact ONLY capable of UV Clarification and therefore should be labeled as UV Clarifiers, but are unfortunately improperly labeled as Sterilizers.
This is an important point, even if you are not interested in improving water chemistry via Redox or killing disease pathogens, as a true UV Sterilizer can "Clarify" a pond much quicker than a UV that is ONLY capable of clarification. Also a true UV Sterilizer often works for green pond clarification when a UV clarifier fails due to high bio load, excess sunlight and other factors over load these devices limited capabilities.
For the UV to properly function in a pond for green water control (UV Clarification), the flow rate should not exceed 40-50 gph per watt of UVC in most Compact UV Sterilizers (such as the Tetra, or Terminator), or 50-70 gph per watt for most higher dwell time straight tube UV Clarifiers (some super high efficiency/dwell time UV Clarifiers such as the TMC Pro Clear UV30 can go to over 70 gph per watt). Keep in mind these numbers are for UVC Clarification, not level 1 sterilization (which requires slower rates and higher pond or aquarium turnover).
Product Resource: TMC Pro Clear UV30
In larger ponds with high flow rates I often recommend more than one UV sterilizer, with a by-pass from the main line to control flow rate, then each unit connected in parallel for best results, although in-line can work too, just not as effectively. Often a separate, slower pump (with a pre-filter) installed for the sole purpose to run the Pond UV sterilizer is the key to success when the main pump line runs at too high a flow rate for the UV to be optimally effective.
For this reason, I also do NOT recommend the popular filters with built in UVs as your Pond's sole UV Sterilizer/Clarifier.
The flow rate is usually too high to work properly. As well, the design of most I have seen and used have too high a gap between UV bulb/quartz sleeve sterilizer compartment wall, which is generally not adequate for good UVC exposure. The FACTS are that these filters with built in UV lights are UV Clarifiers AT BEST, and even then poor UV clarifiers.
A separate UV is always best! I have maintained ponds with UVs in filters and UVs separate and the difference in water quality in the separate UV ponds is significant!
However, do not take this advice to mean no pond filtration is needed, only a water pump and a separate UV run by this water pump is NOT adequate.
For CORRECT UV Sterilizer function, the pre-filtration of water prior to entering the UV is a MUST (even if just encasing the pump with volcanic rock as shown near the beginning of this article).
What is also noteworthy is that while a basic UV Clarifier can clear green water when properly installed, it WILL often takes days when under the SAME conditions a TRUE level one or higher UV Sterilizer (especially a high dwell time model) can take just a day or two or even as little as just hours while also having the bonus of improving fish disease resistance (via improved Redox Balance).
For more information about correct Pond UV sterilization and how it works please visit this site;
Many times I have heard of complaints that their UV did not help with algae control, when I checked this clients pond, I found inadequate filtration and an improperly installed UV sterilizer. Even a properly installed True UV Sterilizer cannot over come poor filtration and a poorly planted pond. As well, many manufacturers make claims of high flow rates that are impossible for proper contact time.
Another common problem I have encountered is a poor circulation pattern where-by the water pick up for the UV Sterilizer was near the water return, with the result that 3/4 or more of the pond water never made it into this flow pattern for proper UVC Sterilization.
To maintain a proper flow rate per watt per gph, connect a ‘T’ in line to your high flow rate pump, from there a reducing bushing (Ex. In 1-1/2” PVC I would step it down with a 1-1/2” by ¾ bushing), from there an in-line ball valve, from there to your Pond UV Sterilizer, then back to your pond or water feature (such as a waterfall or spitter).
Another option is to split the outflow from a large, high output pump and place a UV Sterilizer on each line.
You can also simply add a separate lower rate pump just for your Pond UV Sterilizer.
These diverter valves are listed/sold here: Pond/ Aquarium Plumbing Parts
Please note that these diverters only represent a fraction of PVC sizes and combinations, as well a ball valve may also be necessary on two sides of the diverter if head pressure is too high on the UV Sterilizer return side.
Often it is difficult to determine the flow rates of larger high pressure pond/pool pumps rated in HP (horse power) rather than flow rates that are occasionally used in larger ponds.
This diagram can help determine flow rates at certain head pressures if you own such a pump (please click to enlarge). It is noteworthy that these pumps in 1/2 HP or higher do not even loose flow to head pressure until after 12 feet of head.
Here are a few solutions if the flow is too slow through your UV Sterilizer:
This diagram shows a Via Aqua BH2000 Filter/Pump (similar to the before mentioned Pondmaster or SunSun Pond Filters) connected to a UV Sterilizer via the built in diverter valve. This valve is common to most similar fountains and filters such as the Pondmaster 1700, SunSun CHJ-1503, and many more.
For Small Ponds, self contained Internal/Submersible UV Sterilizers are growing in popularity, however I would caution prospective buyers that the first generation models have problems with electrical failure and are not efficient.
Product Resource: Submersible UV Sterilizer Pump, Filter
I would also point out that while these UV/Filters do provide some filtration, this is intended primarily for pre-filtration prior to water entering the UV-C chamber.
For larger ponds (over 2000 gallons) often placing two UV Sterilizers such as two SunSun 36 Watt UV will be more economical than one larger UV Sterilizer as when used with separate pumps, the flow pattern is often better, therefore the pond "turnover rate" (how often the entire pond water passes through the UV Clarifier) is generally slightly higher than one unit of say 75 watts that often costs more than double the price as well.
Better is a unit with long exposure such as the before mentioned TMC Professional 110 Watt UV Clarifier or a couple of TMC Pro Clear UV30s as compared a Smart HO Two-Lamp 100 Watt UV Sterilizer.
Or as another example, two TMC Pond Advantage Premium 25 Watt UV Sterilizeras compared to one Emperor 50 Watt UV.
Another important consideration with the use of ANY UV Sterilizer for outdoor pond use is protection from direct weather exposure.
If you have problems with a new UV Bulb firing, please see this video and/or read this article:
Finally, while I recommend a UV Sterilizer/Clarifier for most ponds, I find that many pond keepers are too dependent upon this device where as if the UV ceases to function the pond immediately turns pea soup green.
In my experience this indicates a pond that also is in need of better filtration, as the UV Clarifier should be a compliment to good filtration, not make up for poor filtration. The Veggie Filter I suggested earlier is a good idea, or simply adding more filters if your pond has some filtration, but your current filtration is not adequate.
Further Reference: DIY Pond Veggie Filters
 POND ALGAE (Green Water and Blanket weed)
For MUCH more about the control, prevention and treatment of pond algae, please read this article:
Also see this article for information specific to Cyanobacteria:
Cyanobacteria in Ponds, Aquariums
In a healthy pond, with a properly functioning nitrogen cycle, water changes can be minimal. I still recommend a water change of 10-20% per month on a healthy, fully functional pond. In a newer pond larger and more frequent changes may be necessary.
If a lot of leaves fall to the bottom of the pond vacuuming them or raking them out is important to prevent organic buildup.
Water changes also will help with pH and KH if your tap or well water is slightly alkaline and has a KH above 80 ppm.
Your pond filter should also be part of your pond cleaning schedule. With a pressurized filter such as a Pressurized Pond Filter, I recommend cleaning and rinsing once per month during pond season or more often if the flow rate slows down.
Veggie Filters should cleaned and trimmed at least once per season.
 POND CYCLING:
Generally speaking this process is about 99% the same as aquarium cycling, so I would strongly recommend reading this excellent article:
I would add in addition to this article that the process of cycling in a pond takes 6-8 weeks in warm months, but cooler temperatures such as a pond under 60 F can delay this process.
 POND CARE BIOLOGICAL PRODUCTS
For sludge build up products such as SeaChem Pond Stability, Natural Environmental Beneficial Bacteria, or Microbe-lift are useful for aiding in the breakdown of sludge and other organic mulm through the action of bacteria and enzymes.
 POND FOAM:
Foam around waterfalls and other water features is not uncommon, however if this is a persistent problem, there may be other issues at play in your pond.
 POND CHEMISTRY (GH, KH, etc..);
This is important not just for fish health, but also for algae control as well. Besides ammonia, nitrites, and phosphates kept near 0 ppm, nitrates should be kept under 50 and the often forgotten GH and KH should be kept no lower than 100 and 50 ppm respectively.
If your GH is low this can be a problem (with a stable pH) during the hours of the day when photosynthesis is high, even with an adequate KH.
Feeding a quality diet can be beneficial for growth, breeding, color, and even the environment as there is less nitrogenous waste to add to the water column.
This is a broad subject that is beyond the scope of this article, so I would suggest reading more specific articles, here are a few suggestions:
This is far a complete list, however many more can found in our Aquatic Information drop down list in the header bar or at Aquarium/Pond Answers.
One important point I will make and that is the importance of changing water (at least 25%) prior to every single treatment.
The reason is that ponds in particular generally have a high content of dissolved organics, floating algae or similar bio substances, much more so than the average aquarium. These organics will absorb many treatments, especially chemical treatments such as those that contain Malachite Green (such as Quick Cure, which is a very effective pond treatment of many small pond parasites).
By changing water first, this allows for more medications to be delivered to the pathogens causing disease, as well this will generally improve water conditions which in turn helps the fish fight off the infections/infestation better. This can also lower the amount of medication that might be needed to treat your pond as well.
I recommend this water change prior to any and all treatments.
A few suggested pond use treatment products that are biologically safe when used correctly, in particular for prevention are:
 WINTER POND CARE;
It is important in winter to keep at least a small section of your pond open for proper exchange of gasses (O2, CO2), if water can still flow into the pond through a water or aeration device, that will work. A minimum depth of 24” (deeper in climates where soil temperatures drop below 32 F) will provide enough water space under the ice for fish to hibernate (even in the coldest climates, ice will really extend more than 6-8”).However if you live in an area of hard freezes, you may need heaters or a device such as this Pond Master Deicer:
If an aquarium heater is adapted to your pond, make sure that there is circulation near the heater and keep in mind that all you are attempting to do is raise the temperature above freezing, so generally only about 1/2 watt per gallon is all that is necessary for most ponds to keep above freezing (assuming adequate circulation).
For example, a 300 Watt Heater should work for most 600 gallon winter ponds (unless you live in the arctic circle). Make sure to protect the heater from fish or turtles that may break the heater using a cinder block, brick, large rocks, etc.
For a smaller 100-200 gallon pond, such as patio or prefab pond, generally a 200 Watt or smaller heater is all that is necessary to take the edge off the cold.
Product Resource: Via Aqua Premium Quartz Heaters
An aeration device or pump placed about midway from the surface/bottom that circulates upward generally will keep an area of the pond surface free of ice and allow proper gas exchange. In deep ponds over 5-6 feet (1.75 -2 meters), thermal layering, called thermoclines, may exist. This acts as sort of an “inversion layer” similar to how smog gets trapped in the air in Los Angeles. This traps CO2 and Hydrogen Sulfide near the bottom which is dangerous to fish and in this case you need to add water pumps or aeration devices at the bottom.
*Million Air & SunSun Air Pumps
*Pond & Aquarium Pumps
Sometimes removal of fish in the winter is also necessary when the pond is very shallow (under 18-24 inches). I recommend avoiding this if at all possible with larger mature fish as this can injure and often cause more stress than simply improving your pond to deal with winter conditions.
 POND BOTTOM, CONSTRUCTION, REPAIR, SUBSTRATE:
Construction and make up of your pond can be done in three different ways (and there is no one best way; the best way fits your pond size needs, climate and budget).
It is not unusual for a pond to have a leak from either time, poor construction, weather damage, animal damage or "you name it".
 SPRING FED POND (Also water level maintenance);
If you live in an area of natural springs or have creek flowing nearby, this can make for a very healthy, clear and natural pond.
Another method for adding water simply is a float valve. These will add water due to evaporation or loss of water by other means and can even be used with flow through system to automatically regulate water level. Here is a picture of such a float valve by Hagen (Laguna).
 KOI, GOLDFISH, ROSY-RED FATHEADS & GOLDEN/BLUE ORFE;
The Golden Orfe (& Blue), is suitable for ponds. It can grow up to 2.5 feet but usually stays near 1.5 feet. It is a long, slender, bullet-shaped, schooling, orange fish often with black dots on its head and back. Orfes are native to Europe and were derived from the ide which is a silver predator. They need lots of room generally live 10 20 years, however this has not been established.
The Fathead Minnow and Rosy Red Minnow are popular fish for ponds and even aquariums. These small graceful fish do well in similar water conditions as Koi, Goldfish, and Orfe which is higher GH and a pH between 7-8, and prefer temperatures between 50 75 (10-24 C), although they can survive between 33- 100 (1- 38 C).
 POND PREDATORS:
I found Heron decoys such as this one by Hagen: worked well at not only scaring away Herons, but other predatory birds as well such as Cormorants, Owls, etc. (I might note that these decoys do NOT work in breeding season which early March 'til late May where they actually may attract Herons!). I also suggest moving the decoy around as Herons can quickly learn that this is a fake Heron.
This Alligator decoy is another Heron deterrent that others have used successfully (I have not used this method myself, so I cannot personally vouch for it, but it certainly seems like a good idea and I trust those who have claimed to use it successfully).
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