Source of mystery bubbles??

[Palmrat]

A few weeks ago, I noticed small bubbles in water entering the pool thru the return lines. The lid on the pump strainer basket was lubed and tight (no bubbles there), so I called my pool service guy. He found a cracked pump impeller case and replaced it, but the bubbles remained. He changed the lid and gasket on the the pump filter basket, but the bubbles remained. He suspected a leak in the skimmer, so the leak detector company checked, in stages, the line from the skimmer to the pump input and found no leaks. The tech then checked the entire pool system and found one old PVC repair that was leaking, fixed it, but the bubbles remain. There are no visible bubbles in the pump filter basket; no air escapes when I open the filter pressure relief valve. Suggestions?

Pool is a 15,000-gallon in-ground marcite with a sand filter and a Pool Pilot chlorine generator DIG-220.

Thanks for your help.

 

[Jimrahbe]

pr,

Every SWCG pool in the world has the same small bubbles.. They appear when the SWCG is running and go away when the SWCG is resting..

Thanks,

Jim R.

 

[Palmrat]

Thank you very much. The SWCG has been installed for 7 months, but I have only noticed the bubbles recently. Does the fact that the generator is running at a higher level during the summer generate more gas and thus more bubbles? (I live in Florida.) I guess I should have started my research here and saved myself some $!

 

[Jimrahbe]

pr,

Yep.. the harder you run it, the more bubbles it will make.. The speed of the pump has a lot to do with how the bubbles look.. The faster the pump, the more spread out they are, and the slower the pump, the closer together they are.. I run my pump at about 1200 RPM and they come out in little puffs..

Just to be clear, pump speed does not change what the SWCG is doing or the amount of chlorine being generated, it just changes how the bubbles look after being returned to the pool..

Thanks,

Jim R.