Biotope One A Study of Flora and Fauna 
Mattenfilters have been around since the 1950s in one form or another. They have adapted slightly here and there to newer technology and ideas but the same principal applies. They are efficient and easy to maintain for a large number of tanks. They make a great system to use in a fishroom driven by a main air pump.
Mattenfilters somewhat are similar to air driven box filters in the sense that they house microorganisms like bacteria, worms, ciliates, archaea, flagellates, and others. The mat filter itself does somewhat filter out large particles but the microbiota that live in the filter material do all the work.
Tiny little biological beings eat the waste from the tank and turn it into something that can be used by other inhabitants. These inhabitants might be plants, perhaps other micro-organisms that live in the film in and around the mat filter. What is left gets siphoned off and replaced during water changes.
A simple airlift made from PVC or similar tubing pumping water from a corner or end blocked off with foam will do more than an exemplary job at filtering your tanks. The PVC or acrylic tubing can be bent into a 90 degree using a heat gun, hot water, or 90 degree fittings. Drill a small hole and insert air tubing and the airlift pumps circulating water waiting to be converted by the waiting microorganisms.
“Adequate surface flow should be enough if you have trouble with protein membrane on the top of your waters surface. ”
Tom Jensen tells us that he has been using the mattenfilters with more than satisfactory results. He points out a couple areas that most people wouldn’t think about unless you had some experience running them in your tank.
A good side effect of the mattenfilters is that the foam hides your accessories. The lift tube, the heater, and any additional similar gear is out of sight. Hidden away from view especially with a corner mattenfilter or a sideways tank that utilizes a whole rear section as a filter. The mulm that is deposited can be vacuumed away readily and easily.
“Also the HMF corner will hide that great looking inlet and heater. And you will get the benefit of of a great place for the fish to look for micro organisms, and better biological filtration at the same time. Not to forget its fry-proof also.”
Biological filtration is not a new thing in the aquarium nor in nature. Something eats something else and on down the line it goes. Luckily for aquarium enthusiasts nitrifying bacteria inhabit parts of the aquarium we set up and make bad things good. Without something to change the ammonia from fish waste into nitrates and nitrites we wouldn’t be able to keep fish. Mattenfilters tow the line and do their job.
Mattenfilters are very efficient as well compared to sponge filters and canister filters. Sponge filters require more maintenance, and so do canister filters. Mattenfilters really only need to be cleaned when the water no longer flows through and the water level differs. This makes the mattenfilters a much easier way to maintain multitudes of tanks.
Poret makes a top quality foam to be used with mattenfilters. It is a magnificent product that is arguably the best. However there are alternatives like sheet filter media and other foams. Remember that some upholstery foam is suitable but some contains flame retardant chemicals. If you use an unknown foam be sure to test each batch to make sure it doesn’t create an issue with your tank inhabitants.
Another beautiful thing about the mattenfilter is that unlike an overflow in a drilled tank it doesn’t off gas as much CO2, which is great for a planted tank. CO2 is held in solution when it is cool and not agitated. The overflow simply is too aggressive having been thrown over a wall and down a tune into a sump. The mattenfilter is more gentle and loses less CO2 form solution, great for those iwth injected CO2 planted aquariums.
Instead of using a riser with an air tube one can substitute a powerhead if you wish. A short piece of vinyl or similar tubing will suffice, pumping the tank water over the mat wall into the main part of the tank. This is a more aggressive method and s suitable for larger tanks. For those that are breeding fish and raising fry the airlift method would be more suitable.
These filters are cheap and easy to construct. Glass strips can be siliconed into the corners or ends of the tank. There are alternatives, like the plastic channels for hiding wiring and simply using acrylic strips that bend to keep the filters in place. A bit of imagination with what you have on hand would also help create these wonderful filters. Fish rooms that use the narrow side of the tank can turn the far end into an efficient filtration system.
Cleaning should be done when the water levels differ on the opposing sides of the tank. This will depend on the tank’s bioload, waterflow, and type of foam used. Simply remove it and rinse it to clean it of its clogged particles. If using substrate it is simple enough to cut the foam into two sections, one being slightly above the substrate in order to make removing and replacing the mat easy, so that substrate doesn’t spill over into the filtration side.
The mattenfilter risers can be made from PVC pipe or acrylic tubing. Both can be bent using a pot of hot water or a heat gun. The boiling water method is faster but scalding and burns are more likely. If you are unwilling or unable to use boiling or hot water then try using the safer method with PVC pipe and 90 degree angle fittings. Drill and small hole in the top side of the bend to insert you airline. The air bubbles rising pulls water up the riser and over the mattenfilter wall. New water is drawn in through the tank side foam.
This tank side foam builds up a biological film and fish can investigate and find tiny bits of food and organisms. This is a great way to let fish fry especially find new and exciting foods to keep them healthy and entertained
Don’t overlook the mattenfilter for your fishroom needs or even your single tank needs. Its an efficient method of biological filtration and it’s cheap and easy. The easier it is the more success you are bound to have in your fishkeeping adventures. You are sure to enjoy hours of clean healthy fish watching as a result.
Photos courtesy: Tom Jensen and Stephen Thompson
