Sponge filter question

[Fin35]

Hello. I tried to attach my sponge filter to the air pump with a check value but it wasn’t working. Yes I tried both ways. So now I have my air pump sitting on top of my tank above the waterline. I’m safe from draining my tank if it’s on top of my tank and don’t need a check value, correct? Just double checking because draining my tank would be awful. Also my sponge filter floats, will it eventually settle and sink? I have rocks on top of it now.

[Desperado070]

(blow on the check valve and see which side works?)
But you don't need a check valve...

Check valve is only required if there is pressure on the water/cable, which if you got the cable going in from the top, is not the case.

Shut you air pump off and watch the cable.
You will see it raise to water level en then stop.

Depends, if it has air bubbles in the sponge it can float.
But floating is not what it suppose to do, weight it down and keep it down.

[HannahJo]

Desperado is right. If your pump is above the tank/water then it will not drain your tank. I have mine set up this way with no check valve.
If I remember right, my spongey floated when I first put it in. Once it loses the air and gets full of water it should stay put on the bottom!

[Desperado070]

Yes that to but that was not what I meant.
If you take a bottle of water, drill a hole through the bottom and put a air tube in there.
Now when you fill the bottle there wil be pressure on the water in the air tube.
Only then you need a check valve. (only if you air pump is bellow water level)

Actually I have mine big air pump standing on the ground.
I always unplug it when I give live feeding and never had any problems.
You only start to get problems when you pull the air tube out filled with water.
Because only now there wil be pressure on, and the water will flow out.