Sponge filter Q

[majolo]

I got an Azoo sponge filter (This one), and it doesn't really have directions. It lists "features". Anyway, how do I use this? There are two tubes on top, a large and a small. I assumed I would hook up an air pump to the small one and that's it. I tried it, and I just get some bubbles coming out of the large tube. I can't tell if anything is happening with the sponge. Am I doing this right? Also, it doesn't want to stay sunk. (This little filter is for a 5.5 gal snail tank I'm going to set up).

 

[BillD]

Squeeze the sponge, while submerged, to water log it. It is working as it should. It will take time for bacteria to build up on it. The air injected into the large tube causes the density within the tube to be less than the water outside, so gravity forces water through the sponge to replace the water going up the tube. This is how flow is maintained through the filter. Tinyfloating bits will get sucked into the sponge, and the entire surface area of the sponge will become colonized with nitrifying bacteria. This take some time so for a few weeks, water changes need to be done more regularily than usual, to keep ammonia and nitrite levels down, while it becomes active. Regular maintenance is to regularily remove the sponge, and squish out the accumualted crud in a container of tank water. They are simple and very effective little filters used by many, especially those with lots of tanks. Hope that answers your questions.

 

[majolo]

Gotcha. I'm seeding it with some established filter media (just in a mesh bag leaning against the sponge, so presumably it will gradually transfer some bacteria over). It's also sinking better now, it probably had a few gas bubbles left in the sponge (I did squeeze it in water at the beginning). Thanks.

 

[An t-iasg]

I had that sponge fillter in a betta tank. It's a nice filter. That little tiny tube where the airline connects will pull out of the filter body. That feature comes in handy when you need to rinse the sponge - just pull the little tube out, rinse the sponge, and re-insert the little tube. The airline remains connected to that little tube so you don't have to put the airline back on every time. You can also slip the sponge off of the filter body for rinsing.

The bigger bubbles (how many, and how fast) coming out of the large tube are determined by the strength of your air pump. You can regulate the air flow with a gang valve if necessary.