Sponge filter question

[fishfan88]

I just put a sponge filter in my fry tank yesterday, and there are bubbles coming out of the top but it doesn't seem to be filtering anything... There's an airstone that goes down into a tube that fits into the sponge. I don't get how this is supposed to filter though... It just blows bubbles up through the tube. Can anyone help?

 

[Cloudhp8]

I don't know much about them but i believe a sponge filter works like a normal HOB or canister it sucks water up then sends it back in. i think you hook them on the suction side of a powerhead and the sponger catches all of the debris and creates bacteria and keeps small fish from getting sucked up.
To me it would be the same thing to putting a sponge over an intake tube.
I THINK I AM NOT 100% ON THIS

Sounds like all you have is a bubbler. which all that does is...well makes bubbles to add oxygen to the tank (aeration)

 

[Fresh2o]

The performance of an air driven filter depends on how much air is being pumped through it. More air, more throughput (to a point). It may be the case where the airstone is creating too much resistance for the air pump resulting in too few bubbles. You might try removing the airstone and running the sponge filter without it and see how that goes.

One way to see how well it is working is watching suspended particulate matter around the sponge. Are they being drawn into the sponge? Mind you, it will not have the drawing power of a powerhead but for a fry tank it should be sufficient.

Perhaps a picture of the sponge filter in action in the tank might help.

 

[fishfan88]

It's not pulling anything into it... I just can't figure out how to get some suction going... All it is is an air stone in a sponge

 

[Fresh2o]

It's not pulling anything into it... I just can't figure out how to get some suction going... All it is is an air stone in a sponge

That is decent flow coming out of the tube. Be sure to squeeze all of the air bubbles out of the sponge; they will restrict water flow through it.
It is a very simple design; air plus water go out through the top and water is drawn in. You could try without the airstone to see if there is any improvement. Again, the air bubbles in the sponge might be the problem. Good luck.

 

[fishfan88]

Oh ok. Um. I took it out of my tank cuz when I went to look at it again I couldn't see any of the 60+ babies that were swimming around yesterday... I used a net to stir up the gravel and a bunch of dead, chewer up looking fry floated out! I can't figure out why, but now I have only two out of all the fry that are still alive!

 

[Fresh2o]

Oh ok. Um. I took it out of my tank cuz when I went to look at it again I couldn't see any of the 60+ babies that were swimming around yesterday... I used a net to stir up the gravel and a bunch of dead, chewer up looking fry floated out! I can't figure out why, but now I have only two out of all the fry that are still alive!

That does not sound good. Have you tested you water recently? I believe fry tanks are usually gravel free to reduce the amount of waste build up that can harm sensitive fish.

 

[fishfan88]

I know that, but I had gravel in it already and didn't have a place to put the fry I vacuum it every few days though, and tests all come out perfect. I can't figure out what's wrong.

 

[Fresh2o]

I know that, but I had gravel in it already and didn't have a place to put the fry I vacuum it every few days though, and tests all come out perfect. I can't figure out what's wrong.

My first thought was an ammonia spike but idk. How old were they? We're they eating properly? That is odd.

 

[fishfan88]

They ranged from 1-4 weeks old. I feed my fry crushed flakes and brine shrimp when they are big enough. (frozen adult that is) but these ones hadn't had the brine yet. Everything seemed normal Before...