Air bubbles in pump basket. Can't find air leak

Aug 30, 2016
4
Winnipeg
I need help finding the air leak in my pool. I know it is on the suction side and I have tried using incense, water, and shaving cream at every joint/elbow/lid/valve and have had no luck finding the leak. My suction side consists of the skimmer basket, a poly pipe underground connected to a cvpc pipe with a barbed fitting and a 45 elbow. From there it is connected to a valve, a 90 deg joint and then the union that screws onto the pump. I have a Jacuzzi skimmer, a 1HP Jacuzzi magnum force pump, and a Hayward sand filter.

When I turn my pump on there is no air bubbles for about 30 seconds (sometimes a few minutes) then I see a lot of small air bubbles in the pump basket. It runs fine at the start when there is a few bubbles (and there is no bubbles out of the return) but after awhile it builds up and there is a lot of soapy/frothy bubbles at the top of the pump basket (and i start to see bubbles out of the return). I noticed that whenever I start to see the bubbles in my pump basket there is a sound in the 45 deg elbow or just before that in the poly pipe right as it comes out of the ground. It sounds the a knocking sound, or sounds like rocks are rattling around inside the pipe, and you can feel the vibration in the ground beside it. I may try to replace the connection from the polypipe to the cpvc pipe to see if that fixes it.

I doubt there is a leak underground because i dont seem to be losing any water (haven't tried bucket test yet). I filled the pool so the level is not the problem. I bought a drain king and tried to blow out any debris but that didn’t do anything. I also put a hose all the way down the line to see of there was any debris, but there was nothing. I replaced the valve and the lid o-ring.

Can I still run the pump like this so I can clear up my green pool, and does anyone have any ideas of what the fix could be?
 
you didnt mention the pressure side. but based on all the things you have tried on the suction side, it seems you probably have that covered. i mention it because the pump strainer basket can have frothy bubbles if the filter pressure is too high and the pump is struggling.

the rattling sound is strange. do you have only one line into the pump? pictures of your setup would be nice.

you might want to try hosing each joint again with a low flow of water. when i did that it took up to 20 seconds at one location for the bubbles to disappear. not sure how long you tried.
 
Thanks for the reply. I do only have one suction pipe that comes from the skimmer basket to the pump. I will add pictures shortly. I will try the water again as well. I looked online to see/hear what cavitations sounds like and it does sound like it is cavitation in the pipe. What can cause the cavitation?
 
Something else to try. I have a new Pentair Superflo VS pump. I had air bubbles in the pump basket, no water leaks on the suction side, small water leak where the fitting exited the pump (pressure side). Tried the usual for the suction side air bubbles: skimmer, pump basket cover gasket, drain plugs ... no luck. Researched online best way to fix leaks. For screw in fittings: 2 or 3 wraps teflon tape (no more) then coat the teflon tape with a Hercules product called Real Tuff. I remembered I had used the stuff a while ago and even had a jar. Stirred it up, put a good coating on my male screw in fittings (over the teflon tape). I was looking to eliminate the pressure side leak, but I did the suction side also just for the heck of it. This process eliminated my pressure side leak AND GOT RID OF MY PUMP BASKET AIR BUBBLES!
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.