determining leak vs evap rate

[keep-it-simple]

I think we have a leak.
Pool service came out two weeks ago and found some pinhole spots in the liner around the skimmer. Now we're supposed to be watching for leaks and report back before he closes out our bill.

April 30 - May 3 (4 days): day time high of 77, 72x2, 64 and overnight low in mid 50s - no cover on pool - 1/4" lost
May 4 - May 6 (3 days): 5" of rain
May 7 - May 12 (6 days): day time high of 70x2, 73x2, 79, 64 and overnight low in low 50s - solar cover on pool - .9" of rain and water level is down 3" from where I wasted on May 6.

I keep trying to place a bucket on the steps to mark water level inside/outside bucket to see which goes down faster but the current in my pool continues to knock the bucket over even with a brick in the bottom of the bucket. I have the return eyeball pointed away from the steps, b`rs a day - that seems to be the amount needed to keep FC steady.]
Would the results be affected if I measure water level in a bucket sitting outside the pool and visually compare to water line on side of pool? Seems like an inch of water is an inch of water, right?

 

[mas985]

1/4" per day or 1" per week is not uncommon for evaporation. The important factors are the water temperature and the dew point temperature so if you put the bucket outside the pool, it won't maintain the same water temperature as the pool. However, with an SWG, you should be able to detect a water leak by the salt level and CYA levels dropping (assuming no splash out or overflow). Have you been experiencing either?

 

[keep-it-simple]

Yeah... but the past two weekends in a row it rained 4-5" and I had to waste water. So I've wasted 9-10" rainwater in the past two weeks. Wouldn't the rain/wasting also contribute to salt lost?
I've read to expect an inch per week of evaporation. And 1/4" lost over 4 days seems appropriate. 4" down (3" lower plus nearly an inch of rain) over the past 6 days seems excessive.

 

[JasonLion]

4" in six days is excessive. The only way there could not be a leak is if you made a significant error in measuring or somehow pumped out water when you thought you were doing something else.