Evaporation rates

Jleek0151

Well-known member
Mar 26, 2019
50
Illinois
I have been noticing some random water levels drops throughout this summer. Being new to the pool thing I was just wondering how much evaporation is considered normal. Some days I can loose almost an inch or more. Other days I could loose less than an 1/8 of and inch. So far this week I have had to run my hose for 45mins twice a day to barely keep up. It’s has been 80-88 through the day and getting down to the high 60s at night.
Thanks
 

Teald024

TFP Guide
Evap rates can vary widely. It depends on pool surface area, pool temp, air temp, humidity, wind, sunny/cloudy. Dry, windy days with water warmer than air will give the fastest rates. Normal can be around 1/4 inch per day on average.
You can do a "bucket test" where you place a 5 gallon bucket of water, almost full and measure how it compares to water loss in the pool. Both should loose the same amount in theory. Unless you have a lot of splashout in the pool or your dog drinks from the bucket, lol.
Put some masking tape right at water level. wait 24-48 hours and check the levels of both. They should have both dropped by the same amount. If the pool is lower, then you have a leak somewhere.
 

Jleek0151

Well-known member
Mar 26, 2019
50
Illinois
10-4 I have tried that with mixed results. Sometimes the pool looses more and some times the bucket seems to. It rained hard enough a couple weeks ago to fill the pool up to the top of the skimmer. It was cloudy and cooler for 3 days and it showed no sign of water loss. Within 2 days of sunshine and warmer weather it dropped below half way. To me that seems like a crazy amount for evaporation, but doesn’t make since with the 3 days it didn’t show water loss. I’m kinda up in the air with it. All I have to say I’m scared to see next months water bill.
 

Jleek0151

Well-known member
Mar 26, 2019
50
Illinois
I should note that I know my skimmer has a slight leak. When I mean slight I am talking about a drip every 10-30 sec. I feel like that doesn’t add up to almost 500-600 gallons a day of water loss.
 

aboykin2269

LifeTime Supporter
Jun 3, 2015
331
Pittsboro NC
Wow that sounds like a lot. Especially if you say you losing 500-600 gallons/day. If you are consider the hottest heat of the day being what 6 hours? That's over 80 gallons an hour.
Have you noticed any spots of excessive moisture around the pool?
 

Jleek0151

Well-known member
Mar 26, 2019
50
Illinois
Not that I’m aware of. Now the 500-600 might of been a slight exaggeration ?. I think I figured it one day that 2 inches in our pool is about 600 gallons. That would be over a couple days if I would not fill pool. Our pool is surrounded by a deck and rock so it is hard to tell. I feel like I would notice something if I had a considerable leak. Im going to recheck this morning. Water was down far enough now the pump loss prime.
 

aboykin2269

LifeTime Supporter
Jun 3, 2015
331
Pittsboro NC
Sorry you are having this issue. I've been lucky (although I do have to put up with a lot of leaves) but we get plenty of shade on the pool, so evaporation hasn't been that much of an issue. We've only had 2 significant rains since the beginning of June and I have only had to add water twice all Summer.
Good luck.
 

Jleek0151

Well-known member
Mar 26, 2019
50
Illinois
After a long weekend of patching the liner I might have the leak either stopped or slowed way down. I’m down to losing about an 1/8 during the day and a 1/4 at night. Haven’t had time to do the bucket test because of a busy weekend. Hopefully it’s just evaporation now. Plan on contacting a pool place to have the liner replaced next spring.
 
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