(2) Basics, How Sponge Filters Work
(3) Sponge Material Used
(5) Use (Air Pump or Power Head Methods)
(6) Additional Sponge Filters for Small Aquarium, Bowls
(7) Additional Sponge Filters for Breeding or Large Aquarium
(9) UV Sterilizer/Sponge Filter Combinations
(10) Sponge Pre-Filters
(11) Other uses of Sponge Filters (Sump, etc.)
(12) Sponge Media Care/Cleaning
Sponge filtration is an often overlooked type of filtration for both large and small freshwater tanks and bowls, and even ponds or marine aquariums. Many aquarists look past these filters because of their simplicity, but therein lies their quality.
I have used these filters for my aquarium maintenance business for 40 plus years with excellent results in freshwater, saltwater and ponds.
It is also noteworthy that the concept is not new, dating back at least to the early 1960s with the Lustar or Hamburger Mattenfilter Sponges.
(The picture to the left is a Hydro Sponge #1 in a 6 x 6 x 6 Betta tank.)
The best sponge filters (such as the Patented Hydro Sponge Filters) can be used to compliment another filter, such as a power "hang on back" (HOB) or canister filter, or even as a stand alone filter, as per our extensive controlled tests. We found that only fluidized sand bed filters out perform sponge filters for aerobic bio filtration.
In fact I, and many other aquarium professionals, have used sponge filters as the only source of aquarium filtration.
With this in mind, people purchasing one of the many 'Aquarium Kits' sold at Walmart and elsewhere would be much better off with a superior bio-filtration such as our Sponge Filter Kit instead.
As a bio filter, most premium sponge filters (such as our Premium Hydro Sponge Filter) are vastly superior to Under Gravel Filters and even superior to comparably rated HOB filter as per extensive controlled tests performed by us in the 1990s.
This is due to the very porous nature of a sponge filter that allows for extensive colonization of nitrifying bacteria, assuming your aquarium or pond is adequately circulated.
Please note that many sponge filters and even patent infringing "knock offs" made by a variety of brands (such as Lees, Tetra, Hagen, SF-XY, XY-380, AquaTop) are NOT made of the same patented sponge material as ATI's patented Hydro sponges. Thus these do not perform nitrification at the same level, as my tests confirmed in the 1990s, often by a LARGE margin due to a much more porous design that simply traps more debris and allows more bacterial colonization.
As well, these patented sponges have a micro design that does not collapse on itself as readily as other designs. Please read further for a more in depth explanation of this.
These lower end sponge filters also degrade much quicker, as many users can attest to.
In fact in tests using the XY-380 commonly sold via Amazon, using very similar bio load aquariums, I found the amount of organic debris during the same time period to be almost double for the patented AAP Hydro Sponge Filter, thus demonstrating a MUCH higher capacity!!
The bottom line is there is a reason for the patent and why ATI is constantly legally battling these knock offs for patent infringement when they try to improve.
A couple of the reasons for better test results when compared to an under gravel filter, is that a well designed sponge filter does not have “dead” spots, nor do sponge filters trap decomposing organic mulm in pockets, such as is the case with under gravel filter plates (which can lower KH/pH, increase nitrates, and even promote Aeromonas or Saprolegnia pathogens!)
In addition, these tests showed that these filters were also superior to most popular power (HOB) filters for bio filtration (such as the Marineland Bio Wheel).
Bio Wheels are touted for their ability to host beneficial nitrifying bacteria and yet, this simple sponge filter outperformed them.
Please see this article for more specific information on Bio Wheels:
Bio Wheels: Do they Work?
*Patented Hydro Sponge Filters
*Aquarium Sponge Filter Kit
*Aquarium, Pond Nitrogen Cycle; Nitrification
*Aquarium Chemistry; Correcting KH/pH
*Saprolegnia; Treatment, Lifecycle in Aquariums
Some Positives & Negatives of Quality Sponge Filters:
Using a sponge pre-filter extends the time between cartridge changes in power (HOB) filters, slows the accumulation of organic debris buildup inside a canister filter, and prevents fish fry from being sucked up the intake tubes of the filters.
More importantly, a sponge pre-filter can add some very essential bio filtration redundancy to often woefully inadequate HOB filters that frequently lose much of their bio capacity with each filter change.
The picture to the left demonstrates the use of a prescription bottle for a DIY carbon filter. This can be placed under or behind a sponge filter where the water current is stronger. I have found this to be very useful in tanks where the sponge filter is the primary filter in a small aquarium such as a Betta tank.
In this picture API's AmmoCarb is being used.
Often, aquarium filter kits that are made up of quality sponge filters along with air pumps or power heads are superior to many of the aquarium kits that are sold in the bigger pet stores.
These are the "starter kits" that come with a small tank and are often very basic aquarium power filters, or even basic corner filters (or similar) with little bio filtration capacity. Beginning aquarists would be better served to consider a simple power head and sponge filter in their first tanks!
This is especially true of big box department store or chain pet store kits that rarely have the bio capacity of a sponge filter kit such as one that utilizes an ATI Hydro Sponge. Simplified maintenance along with superior bio filtration capabilities would equal greater chances of success for beginning fish keepers.
Here are some Basics about Aquarium Sponge Filtration; How Sponge Filter Work:
Sponge filters work by having aquarium water drawn through the porous sponge material in which debris from the water column is trapped mechanically.
The type of sponge material can affect both mechanical and biological filtration. This is where many of the cheap knock offs, or even name brand sponge filters such as the Lees sponge filter, do not perform as well. Not all sponge materials are created equal! These utilize pores that are too fine and are made with a foam material that is too dense resulting in poor flow, clogging, and a far less than desirable biological function.
A good test of the quality of the sponge material is when you go to rinse/clean the sponge. Upon removal, the patented AAP Hydro Sponge filter along with all others will likely drip some of the trapped "yuk" from your aquarium while removing if you are not careful due to material trapped just at the surface.
The picture to the above shows the two types of patented sponges made by ATI/AAP HydroSponge where the pore density is obvious and quite different from just about any other sponge filter available.
As noted, this material as per my test has far more bio/mechanical capacity than any of the cheap foam sponge material used in most common and Chinese knock offs. As even the DIY or similar products using poret foam (such as used by SwissTropicals) still does not match capacity as per my use/tests.
It is also noteworthy that while these knock offs have not gotten the sponges right, they have copied the patented modular design, so when you purchase these knock offs such as the Deep Blue or Aquarium Solutions, you are infringing on a patent.
Back to flow, the reverse situation can be a problem with certain reticulated sponges when used in the wrong flow environment. Although the ATI Hydro Sponge is the best in sponge filters, their patented reticulated sponge material is best used in higher flow rate environments instead of their patented standard sponges.
As an example, I do NOT recommend the Hydro Sponge PRO Filters in small sizes such as the #2.
As another example, I have run aquariums with just one Hydro Sponge #2 using the PRO (Filter Max #3) sponge (making this a #2 PRO Sponge Filter) with a common mixed community tank. While this is an excellent sponge for higher flow rates, especially mated to a Filter Max #3 Pre-filter, it performed poorly in clearing debris and murky water.
The key to understand is that while the standard fine sponge actually has more pore capacity than the reticulated, in a high bio load environment with larger debris in the water column, it can clog the outer pores not allowing bio capacity in the inner part of the sponge, thus in essence lowering the bio capacity when compared to the reticulated sponge. This is less likely with the smaller sponge which are generally used in smaller, lower bio load aquariums.
So if "fine" filtration is needed, the standard patented sponge from ATI is best & actually has a higher capacity (assuming it does not clog quickly due to high amounts of more coarse debris in the water column).
You could also combine filtration types (coarse & fine) by using a Hydro Sponge #5 PRO with a #5 Stackable attached (which is a standard sponge). Using a Hydro Pond #2 or #4 and replacing one of the reticulated sponges provided with a standard #5 would also work.
Sponge Filter "Seeding":
You can also "seed" a new aquarium for a faster more efficient cycling period.
Seeding the sponge media biologically:
You also can simply place the filter in your aquarium and allow the sponge filter media to establish itself biologically. There are many other methods that work well, some are discussed here:
Reference: "The Aquarium Nitrogen Cycle" Product resource:
*Stackable Sponge Filter
If you would like more information on sponge material, please see the following article:
Sponge Media Material
FURTHER SPONGE FILTRATION INFORMATION
How a Sponge Filter Works/Functions
When your Sponge Filter is attached to an air pump, the rising column of air bubbles in the tube pulls water with it. The bubbles rise because they are buoyant and the water is pulled along behind them. A larger diameter lift tube allows for a higher flow rate (this is where Hydro Sponge filters excel).
You can measure the water flow (which can be useful to know) by slightly tilting the filter with the top of the outflow just above the aquarium water line and timing the fill rate into a pitcher or gallon jug. If it fills the jug in 30 seconds, you multiply 2 times per minute times 60 or 120 gallons per hour.
You can also add an air stone or air diffuser to the end of your tubing in the outflow tube to produce more bubbles and more lift.
Click on picture to the left to enlarge
Here is a video comparing the use of an air diffuser and standard air stone:
How to Determine Water Flow when an Air Pump is Used to Power your Sponge Filter:
The air pump method is generally the better choice for these reasons:
Sponge Filter/Air Pump Combinations Suggestions:
See this 48 second YouTube Video for some depth comparisons:
As a note for those employing an air pump to power their Sponge Filter;
A bigger difference between some of the cheaper Walmart brands and even the SunSun YT versus the Million Air, Fusion and some other better models is the rubber armature and other parts such as the diaphragm are not thick enough or of poor quality rubber. This results in a pump that get much more noisy over time and much more quickly than the better quality pumps due to the rubber stretching/degrading/tearing. However as per initial noise, often the cheapest air pumps are no noisier out of the box.
If noise is an issue, make sure your pump is not on a hard surface where it can vibrate, also for better "noise protection", placing your pump in a small box wrapped in old socks or similar has worked for me with my clients who are sensitive to noise.
When attached to a power head, the pump pulls the water thru the sponge.
With a power head, you will not see any bubbles flowing up the lift tube as with an air pump. However, with both methods there is a rising column of water through this tube that in turn is pulling water through the sponge filter material.
The Hydro Sponge #5 can handle flows up to 400 gph (depending on bio load), if a higher flow is required, the Hydro Pond Filter #2 or #4 can also be used in an aquarium (I have often used the Hydro Pond #4 as a pre-filter for high gph pumps in wet dry sumps).
The power head method is generally the better choice for these reasons:
Please see this short video highlighting the differences between an air pump powered sponge filter or a power-head powered sponge filter:
The picture to the left shows a simple suggested large aquarium set up using a Hydro Pond #4 Filter (a Hydro Sponge #5 would work well too) and the differences in flow using either air pump or a power head.
For tall/deep aquariums; the use of lift tube extensions can be used to provide a better flow pattern.
If you desire less agitation when using an air pump to power your sponge filter, I recommend cutting the top of the lift tube as close to the surface as possible. I also recommend using an optional air diffuser with your sponge filter which will produce a smaller bubble than a sponge filter used without a diffuser, thus resulting in less agitation of the water.
These two pictures show sponge filters set up with basic power head pumps such as the newer generation SunSun JP-23 pictured here (similar to many other older generation basic power heads such as the Marineland, Maxi-Jet or AquaClear).
To snug the fit even more, often the use of Teflon Tape or even a thin ribbon of Duct Tape wrapped around the top of the power head intake strainer will make for a more snug fit.
I should also note that, while these diagrams shows a secure fitting for many aquariums from my experience, for large fish (such as adult South American Cichlids), I would suggest using heavy rocks to brace the sponge filter & power head as these fish will often knock the power head off the lift tube.
As the reader can see, the power head can be mounted directly on the Sponge Filter or on the lift tube and each have their advantages:
Please Click on the pictures to enlarge for a better view
Readers should note that many power heads including the one pictured include a nipple on the outlet nozzle; this is for attaching an air intake diffuser tube which is little more than an air line tube that draws in air for futher aeration of the aquarium via the water current exiting the power head water pump.
In most instances these will not work if the pump is much more than a few inches below the water surface. It is also noteworthy that these small air line rubes often get build ups of hard water that need to be rodded out with a paper clip or similar DIY tool so as to allow free flow of air.
*Hydro Sponge #5
*Hydro Pond #2
*SunSun JP-23; New Generation Aquarium Power Head
*Marineland Power Head Pump Review
*Maxi-Jet Power Head Review
*Hagen AquaClear Power Head Pump Review
Additional Sponge Filters for Small Aquarium, Bowl Applications
Additional Sponge Filters for Breeding or Large Aquarium Applications
The use of these sponges, especially the Hydro Sponge 5 Stackable also allows for expansion with larger tanks, often with surpassed bio efficiency and ease of maintenance over frequently over-touted canister or wet-dry filters.
Here is a basic sponge filter installation video:
SPONGE FILTER TROUBLESHOOTING
Although mechanical filtration is not the main strength of a sponge filter, it can still remove copious amounts of debris from the water column when properly connected using the optimum grade of sponge material for the bio load.
The picture to the above/right (Please click to enlarge) shows water flow through a sponge filter depending upon air diffuser, airline tubing, and lift tube placement.
As you can see, a sponge filter with no lift tube and with no extension of tubing (or air diffuser) has a poor flow through the sponge material (if any flow at all).
The point is to overcome the resistance of the sponge material with a stronger vacuum produced in the lift tube. Additionally, an extension of airline tubing into the sponge filter and/or the use of an air diffuser or air stone can extend this vacuum deeper into the sponge filter, thus providing a better flow.
When new, sponge filters have a tendency to float. Air will remain trapped inside the sponge pores. You can correct this with several squeezes of the sponge. You should be able to clear most of the fine air bubbles that can cause floating.
However, some lower quality sponge filters such as the Lees or Tetra, tend to trap more fine air bubbles. They also have poorly weighted bases (if any). Floating can be a major issue for these cheaper filters that requires placing a rock or similar weight on top of them to deal with this problem.
*Not Trapping Debris:
This is likely caused by incorrect installation so that air or water flow is not properly pulling debris into the sponge, please review the pictures throughout this article for correct set-up/installation.
Sponge media that is also not cleaned often enough, is set up incorrectly, or is of low quality will also have a chance of releasing debris back into the aquarium when cleaning.
Finally with many cheap Sponge filters that have become common of late, these are simply not that porous and simply cannot trap much when compared to the patented AAP/Hydro Sponge Filters.
UV STERILIZER SPONGE FILTER APPLICATIONS
*The first shows a ReSun King 1A Pump connected horizontally to an AAP Hydro Sponge #3 Filter. You will note the use of Teflon tape or vinyl tape to make a more solid connection. One inch vinyl tubing can also be used between the pump and lift tubing.
*The second shows a Via Aqua 480 or SunSun JP-23 Power Head also connected to a Hydro Sponge #3 Filter mounted vertically.
Other ideas would include a larger AAP Hydro Pond #4 connected to a higher flow pump, such as a Rio 1700 Pump for a larger tank such as a 100 gallon aquarium.
With the first two examples, a Terminator 5 Watt UV or the TMC Vecton Premium 8 Watt UV sterilizer will work.
With a higher flow rate (such as a Rio 1700 or similar pump), consider a Terminator 18 watt, TMC 15 Watt Vecton, or a 25 Watt Vecton UV Sterilizer.
SPONGE FILTERS AS PRE-FILTERS:
Besides the more common stand alone sponge filter, the sponge pre-filter is also a viable sponge filtration option. These are especially useful in preserving viable nitrifying bacterial colonies in HOB filters during changes of filter media, especially with cartridge filters that don't have other means of maintaining bacteria., as many of these filters lack bio media chambers
Sponge pre-filters such as the Filter Max can be attached to the intake of most canister or aquarium power (HOB) filters.
Besides extending the length of time between filter cartridge changing in an HOB power Filter, as with other good sponge filters, these pre-filters will increase bio capacity of your over all aquarium filtration.
The only drawbacks are that your filter must have a cylindrical intake tube (which rules out some Marineland filters) and that you do not achieve the filter redundancy in the same way as having a separate Sponge Filter.
The type of sponge material also affects the flow rate, as the AAP Filter Max #3 uses a patented reticulated sponge material that only traps larger debris and clogs much slower, while the Filter Max #1 and #2 have the original ATI Sponge material that traps smaller debris, but also does not allow as much current and clogs more quickly.
Here is an excellent video showing attachment of the Filter Max Sponge Pre-Filter
OTHER SPONGE FILTER USES
Another use of Sponge Filters is as a basic Pond Filter or using a Hydro Pond Sponge Filter as an excellent and efficient large flow pre-filters in aquarium sumps for both salt and freshwater aquarium systems.
See the picture to the left as an example which also includes a Filter Max over the intake to the sump.
These same Hydro Spond Filter that are designed for small pond use also make excellent high capacity bio filters for large aquariums.
Pictured are a water driven #3 to the left with a Rio 20HF pump and an air driven #2 to the right
These have the advantage of being easy to tuck up high in an aquarium corner more out of the way than a standard sponge filter.
The disadvantage, especially when compared to the patented Hydro Sponge filter line is their sponge bio capacity is much lower based on the size and efficiency of the sponge material.
The sponges (foam inserts) found in filters such as the Aqua Clear Filter also qualify as a sponge too. But they are not sponge filters in the classic sense.
One little “trick” I like to do with these sponge inserts is to cut them in half or even thirds so as to “seed” multiple sponges for use in helping jump start the nitrogen cycle in other tanks or as back ups to other tanks under treatment.
Back To Top
PROPER SPONGE MEDIA CARE:
The main problem with sponge filter media of any type is clogging due to mechanical filtration.
The best method is to collect used aquarium water in a bucket from a water change and squeeze the sponge several times until nothing more is expelled from the sponge. This water is then disposed of and new water can be added to the aquarium to replace the water used for sponge cleaning.
To prevent too much dirty water returning to the aquarium when removing a sponge filter, sponge pre-filter, etc., I suggest having a small container to catch the water that might pour back as soon as the sponge is removed above the water line.
This said, based on considerable experience using many different sponge filters over the years in literally 1000s of aquarium applications, with the best designed & patented sponges, what little "gunk" does fall back into the aquarium is but a very small fraction of what you will often rinse out. Often the AAP Hydro sponge will require multiple rinses before the water is mostly clear due to the high bio and mechanical filter capacity.
With ATI/AAP sponge Filters and Filter Max, all sponges are interchangeable, so as an example you can easily add a Hydro Sponge #3 sponge to a Hydro Sponge #2 frame (the exceptions being the Mini, #1 Filters, and the #1 Filter Max).
Often as the sponge material ages from use, it will clog quicker too and again lessor quality sponge material will also break down more quicker than the better patented sponge material.
It is best to add an additional sponge to your aquarium ahead of time to allow this sponge to “seed” with aerobic bacteria.
Here are a Few Myths:
Hydro Sponge Review from Renee (goldenpuon) from “Everything Aquatic”
"I thought I'd write a review of the Hydro Sponge filters I purchased from Carl a while back. The results are excellent too.
Better than any sponge filter I've ever owned. It picks up fish waste very well and now I have to do less than half the cleaning for my tank. I had a guppy tank I was cleaning every two days with a micro filter installed. Now all I have to do is clean it every 1 1/2 weeks!
Hope you guys like my review. I'm not just pointing out the positives here, they really are true."
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