Micro bubbles comming from my sump

[fishfreek]

Yippie....

I finally got all the components of my sump in and I started her up this morning only to discover that somewhere air is being introduced to the return lines as I got microbubbles being ejected into the tank from the returns.

I have no idea where these bubbles are comming from as the lines going into the sump are not producing any bubbles in the sump itself. So there has to be air traped in the plumbing somewhere right? I took a bit of airline tubing and tried to jimmy it up to the highest locations on the return lines to suck the air out but all i got was water.

Any one have a clue?

Could the PVC not be sealed all the way on one of the joints? Wouldnt I see water dripping our of this hole also?

[Bang Guy]

Internal or external pump?

A leak large enough to introduce micro bubbles can easily be small enough to be water tight.

Another thing I've seen is cavitation from the input to the pump being restricted somehow. This usually only happens with high pressure pumps though.

If your pump is external go around all the seams with PVC glue and see if that stops the bubbles.

Also make sure that there's no whirlpool forming inside the sump above the return. This usually only produces sporatic bubbles.

Guy

[fishfreek]

External pump.

Little giant model 4-MDQX-SC

I discovered the source of my air leak. It was a ball valve I had put in place to try to regulate the pump flow rate some. I took the ballvalve out and the air bubbles where gone.

Now I have the issue of my pump pushing to much water for the overflow. Im gonna try to add a third U tube to see if that helps. if not I guess Im gonna have to get a small overflow and use it also.

[reefrunner69]

Try replacing the ball valve. Was it glued in place?

[fishfreek]

No was not glued. Was threaded on both ends and was screwed in place.

[reefrunner69]

Some posts back, when you were deciding whether to go with threaded or non threaded, Guy postedd about some stuff that was better than plumbers tape, might try that. I personally prefer t true union valve, these have O rings for disconection, and are glued in place, and are water and air tight.

[fishfreek]

Well its NOT the ball valve. I was sitting here and thought hey if I put the ball valve IN the sump it wont mater if its leaking air cause it will be under water. So i put the ball valve in the sump and I still have the bubbles.

I have two returns and they are comming out of both so that would mean the bubbles are being introduced prior to the T conector that splits them off right?

[Bang Guy]

Ball valve in the sump?? OK I believe we are getting closer.

Did you have the ball valve before the pump or after?? It needs to be after. If you restrict the input to a pump it will cavitate and form microbubbles It will also reduce the live of the pump. Restricting the output of the pump is fine and will not cause any problems. So... put the ball valve after the pump and you can slow it down that way.

Guy

[fishfreek]

GUY your a GOD!

You get 50 Kudos points for solving my mystery.

I was really starting to get pissed. Would not be so bad if I had not gotten 4-5 cuts on my hand from this whole ordeal.

U know a PVC cut is alot worse than a papercut and a steak knife cuts your hand much better than it cuts plastic hose.

The placement of the ball valve was eveything. Now that its just after the pump no air bubbles are being introduced. All is well.

[Bang Guy]

Thank you and you're welcome

I'm glad everything worked out!

[fishfreek]

Well im still getting some micro bubbles but its not near as bad as it was before. Im gonna try to add a third U tube to the overflow and then beable to take the ballvalve out entirly.