Bucket Test: Is 1/4" Difference in 24 Hours Significant?

[Shocking]

I performed two bucket tests for leaks, during times with no swimming, rain, or water replacement. Both times I got exactly 1/4" difference between bucket and pool water level after 24 hours. Is 1/4" a significant difference? I'm being careful, and results are consistent.

I think I may have air bubbles in the line returning to the pump, and that's what motivated the tests. Would 1/4" in 24 hrs confirm that suspicion?

Thanks!

 

[jblizzle]

There should not be any difference if you did not have a leak.

Is the bucket nearly completely full and at the same level as the pool? If the water is low in the bucket, the sides of the bucket could protect the water inside from higher evaporation caused by wind.

 

[zea3]

I don't think 1/4" difference is enough to call it a leak. Are you seeing air accumulate in the pump strainer basket? If so you will want to check the above ground pipe joints, the o-ring on the pump strainer lid, and the drain plugs on the pump. Check the pipe joints by drizzling water across the joints while the pump is running and watching for the water to get sucked into the joint. Check that the o-ring is in good condition, remove any debris and lube it well with silicone lube. Check that the drain plug on the pump strainer pot is snug.

 

[Shocking]

jblizzle, water levels were near the top of the bucket, so much so that I could only do this test without people swimming and raindrops splashing. So the 1/4" is not likely to be evaporation difference.

zea3, I accept your experience that 1/4" isn't significant, and that's what I was asking for. However, the air can be heard at the pipe as it emerges from the ground, upstream of the various components you named. Reading your post I did learn a lot about leak testing, but I'm afraid this leak (if there is one) is underground.

So far I'm still inclined to suspect a leak. Does this sound reasonable?

 

[Richard320]

jblizzle, water levels were near the top of the bucket, so much so that I could only do this test without people swimming and raindrops splashing. So the 1/4" is not likely to be evaporation difference.

zea3, I accept your experience that 1/4" isn't significant, and that's what I was asking for. However, the air can be heard at the pipe as it emerges from the ground, upstream of the various components you named. Reading your post I did learn a lot about leak testing, but I'm afraid this leak (if there is one) is underground.

So far I'm still inclined to suspect a leak. Does this sound reasonable?

I agree, it sounds like a leak. Between the leakage and evaporation, you're talking over 2" a week in the summer! If you're hearing leakage, you have a leak.

 

[Shocking]

Thanks, all. I'll pursue and post back if something interesting emerges. Meanwhile, you've taught me a lot already about bucket tests and leak finding.