Sponge Filter Noob Question

[jonclark96]

I have a Rena 300 air pump (manufacturer rated for 75 gallons - whatever that means) running 2 hydro V sponges. How can I tell if I am getting flow through the filters? Is this pump big enough? Each filter is in its own tank (1 20L, 1 29G). Is it possible to have too big a sponge filter on too small an air pump?

You collective experience and advice is much appreciated.

 

[Frank Cowherd]

The basic way to tell is to see that there is a good stream of air bubbles coming up. The bubbles reaching the surface should cause a roil of about a half inch. Also you can make the sponge filter work better if the air comes from the center of the sponge. Some sponge filters allow an air tube to be extended farther down into the hole in the sponge filter, the others cannot be changed.
Also, after being used for a month or two or more, depending on how much you are feeding, the sponges should be cleaned to remove the accumulated sludge. It is best to do this by collecting some of the water you remove when doing a water change, and squeezing the sponge in that water repeatedly until does not produce a cloud of dirty water when squeezed.

Hope that helps.

 

[toddnbecka]

I prefer the hydrosponges too, recently replaced a couple of the sponges with the new open-cell foam and upgraded a IV to a V in a 29. I use a large dual-outlet whisper air pump on a 2, and Tetra deep-water air pumps or aquaclear 30 powerheads on the others. I've found that the best way to clean them is to stick both thumbs into the center of the sponge and squeeze it in a bucket of tank water while rolling it with my fingers.
IMO bigger sponges are better, more capacity to collect and hold debris. Stronger water flow through the sponge will pick up more, but with air pumps there isn't a huge difference as long as there's some flow.

 

[jonclark96]

Thanks for the input guys.

 

[bschuhart]

Divider type foam filters -another option

Here's a link (video) I found that uses a small water pump insted of air for a divider type foam filter. They also sell smaller custom cut pieces of foam, so you don't have to spend $100-200 on a big piece of foam just to try it on one tank...it's about 4 cents per cubic inch.

http://www.angelsplus.com/FiltersCustom.htm