Microbubble problem

[stlouisguy]

From the main return pump, where would the microbubbles be formed, before the pump, or after the pump? Im guessing before but cant figure out where the air is getting in

 

[MayoBoy]

They come from 1 of 2 places:

The suction side plumbing has a leak

or

The suction side plumbing is too small and it's causing a vacuum at the impeller which is liberating air from the water.

(Edit - there are some instances where it can be a venturi effect on the pressure side but that is relatively rare. Are you using loc-line or a straight discharge?)

 

[DrBDC]

Yes and yes. Obviously if air bubbles are entering, they will be leaving too. But if the output has a small airhole it can create a venturi-like action and suck air in.

 

[stlouisguy]

Suction side has no water leaking, but I guess it could have air intake

Piping is recommened size with 2 feet before entering pump

Output is through 1 1/2 pvc so no pressure there

 

[TWINPEAKS]

I have had ball valves leak air around the handle when on the suction side.

 

[MayoBoy]

The water won't leak on the suction side - it will just draw in air. Get some food coloring and drip it around each joint one at a time and see if it gets drawn into the tank.

or

Plug the suction end and put a air compressor on it and spray the joints with a water/soap mixture.

 

[stlouisguy]

<a href=showthread.php?s=&postid=8451185#post8451185 target=_blank>Originally posted</a> by MayoBoy
The water won't leak on the suction side - it will just draw in air. Get some food coloring and drip it around each joint one at a time and see if it gets drawn into the tank.

or

Plug the suction end and put a air compressor on it and spray the joints with a water/soap mixture.

I like the food coloring idea I may just wrap each joint with electrical tape which should fix it

 

[MayoBoy]

You could also "paint" each fitting with PVC cement while the pump is running. The cement should be sucked in and seal the bad joint.