I decided to set up some fry tanks under my main tank as I wish to concentrate on breeding tropheus again however didn’t want to have separate filters for each and was trying to work out the best way around this. I discovered that a lot of people us sponge or foam filters in their fish house’s which also go by the name of biochemical filters.
These are run on a standard air pump which allows multiple filters to be run from just 1 multi outlet air pump or an air pump outlet which is split using T connectors. There are twin versions like the one pictured above as well as single versions and come in various different sizes and capacities. I will not list them all here due to most being made in China and no specific brand that you should look out for.
The biochemical sponge filter works by drawing air in to the bottom (through your air pump) and out of the top which creates a syphon and sucks water through the sponges. To add to the effect you will have bubbles from the air pump coming out of the top too which of course gives much desired water surface agitation so there’s no need for a second air pump with air stone as this is taken care of too.
The best place in the UK to buy if they don’t have them in your local fish store would be on eBay and they are extremely cheap. I picked up 4 units of the twin version pictured above for £15 in total!
They are currently running an 18″x10″x10″ fry tank each and all have a Tetratec APS 50 air pump running on them. It could be that you could run multiple biochemical sponge filters from one air pump however this adds to the risk of failure – if your air pump stops working then none of your tanks will be filtered. Please be careful and ensure you use a non-return valve when connecting the biochemical sponge filter to your air pump so as to avoid any water running back down the air line if your pump fails and draining out your tank.
Believe it or not, these are very easy filters to cycle too, if you leave them in a matured tank for a week or so then beneficial bacteria from your mature tank water will soon colonise the filter sponge. Add this mature tank water to your new fry tank or tank with these filters in and away you go!
These are generally not seen as a filter you would use in a display tank or something in your living room due to the size required being a bit of an eye saw but ultimately it is of course the same principal as having an internal fish tank filter or a canister filter running on your aquarium.
It is always advisable to wash the foam (as you would with any other filter) under tank water and not straight under the tap. This is to ensure you maintain the beneficial bacteria which has accumulated within the sponge filter.
I would highly recommend biochemical sponge filters for fry or hospital tanks or if you are going down the route of a fish house or fish room with breeding racks etc. then these filters are definitely a strong option to consider.
hygger Aquarium Double Sponge Filter Super Biochemical Filter Sponges for Aquarium Fish Tank Up to 150L Aquarium Filter with Media Container for Fish Tank Oxygen Increasing and Cycle (Filter)Features:
- Sponge filters provide both mechanical and biological filtration — Provides the ideal location for bacterial colonization and the sponge traps larger waste particles mechanically cleaning the water without trapping baby fish
- Double 10-layer ribbing shape sponges design — it quickly established a bio-filter and extra oxygen, two sponges means more surface area for beneficial nitrifing bacteria to colonize and faster cycling, keeps your fish tank water super clean and crystal clear
- It has a media container with ceramic bio filter media inside, will help to remove harmful substance and provide extra cleaning power. it also comes with 4 sponges, you can replace the filter media to enhance water quality
- Easy to use: using an air hose, connect one end to you air pump and the other end to this filter. The water flow exit tube on the sponge filter is adjustable so you can change direction and height of the water flow
- 【Max Tank Size: 150 Liter】Comes with 2 suction cups to stick to glass, can be installed anywhere,it can also be used as a prefilter or secondary filter; perfect for shrimp tank, betta tank, breeder tanks, turtle tank, goldfish, discus, crayfish, fry, baby fish or other fish. NOTE: It cannot be included pump & clue
- Pleasantly quiet, thanks to sound-absorbing chambers
- Special vibration-absorbing rubber feet
- Excellent quality and reliability
- Highly consistent air flow thanks to powerful, durable membrane
- Includes air tap for adjusting the air flow