tiny air bubbles from powerhead

[Deserter23]

These tiny air bubbles that shoot out like shotgun feed from my Maxijet 1200 are freaking out my fish. This has been going on since 1am last night at a rate of every 5 or 6 seconds. I cannot figure out why this is happening.

I have a 24g nano and I have the powerhead in the 3rd (far right facing cube) chamber. This chamber is only filled about half way with water at all times since the pump turns the water over pretty rapidly.
Although this chamber is not completely full, the powerhead is covered with water at all times so I cannot fathom where the air bubbles are coming from.

I explained all this to one of the helpful employees at dolphin who believes I may need to raise the water level so that water does not cascade as much from chamber two to chamber 3, which could then explain water turbulance in chamber 3 and lead to the powerhead taking air in. I checked this hypothesis and although the water cascades a bit it does not really cause turbulance.

I am completely stumped and my fish are HATING LIFE right now.

Anyone know what the problem could be?

 

[fancyfish]

how much is the pump covered. maybe if you lower it a bit this wont happen. also perhaps you have some cavitation. if so just shake the pump a bit while in the water and see if some air bubbles will come out.

 

[sfsuphysics]

Well air comes from somewhere, that much for sure.

Now I'm not familiar with "self-contained" cube tanks, but sounds like the Dolphin guys are probably pretty spot on. If water "falls" into another body of water it will push air under the surface of the water in the form of bubbles that can get sucked into a powerhead. Another possible scenario is because you mentioned the water level only being about halfway if the pump is too close to the surface depending upon the power it can create a little vortex that pulls air down into the power head.

If it's doing it every 5-6 seconds try to look right at the powerhead if you can, you'll usually see the air going in. As for a solution, raise the water level a bit and see if that fixes things.

 

[dantodd]

I'd try increasing the water level a little bit and add a small square of floss over the powerhead to help capture any bubbles that might be entering the chamber from the water fall.