micro bubbles from power heads

[freshmaker]

I've got 2 Powerhead 420's in my tank and they both seem to blow micro bubbles almost as if they were pulsating. I can't figure out where these bubbles are coming from as both powerheads are completely under water. I've taken them out and cleaned them. As a matter of fact they were doing it when they were brand new.

Does anyone have any idea what would be causing this and how I can stop it from happening short of buying two new (different) powerheads?

 

[Bang Guy]

Cavitation can cause microbubbles. This can result when the input to a pump or powerhead is restricted. Do you have any type of sponge or anything on the intake?

 

[freshmaker]

I don't have anything blocking the intakes at this time. It's funny you should ask. I've been looking for some way to do this because my turbo snails keep walking into the intake and by the time I get home, they're given up.

 

[fishfreek]

how far below the surface level are the PH's?

If you rotate the power heads slightly from side to side do you get a burst of bubbles? You could have an airpatch in the powerhead from when you put them in the tank. I always turn the PH's on after they are under water and rotate them round some to get any air bubbles out.

 

[freshmaker]

They are about 1/4 to 1/2 inch below the water surface. I may need to just give them a little shake to brake up any trapped air.

 

[Anemoneman]

Being that close to the surface, they could be pulling a tiny vortex into the outflow, introducing micro bubbles. Is there a dent in the water surface above the outlet(s)?

Mark

 

[Bang Guy]

I don't have anything blocking the intakes at this time. It's funny you should ask. I've been looking for some way to do this because my turbo snails keep walking into the intake and by the time I get home, they're given up.

I use the bottom half of a heater guard. They are made by Tronic and cost about $4. Keeps the critters out of the intake and doesn't restrict the flow. They fit the intake for the AquaClear 402's and 802's perfectly. Your mileage may vary.

 

[freshmaker]

Thanks for the advice.

Happy Reefin'

 

[CaliGal]

Two more cents here, concerning critters running into the powerhead intake tube.

I have successfully siliconed to this opening the small black plastic 'baskets' that freshwater plants are sold growing in. I've had no causalities since using these little gizmos, thankfully.

Sue