curious-any reason pH would rise due to solar cover on several days?

[pookiesunshine]

my pH rose from about 7.3 to 8 in about 5 days. it had been holding steady so i didnt test it for a while. solar cover was on for 3 nights/2 days during a cold front. no chemical additions other than bleach. would it being covered that long cause the pH to rise?
test results several hours after removing cover:
FC-6.5
CC 0
ph about 8
TA-100
CH not measured

i have some acid to add if it stays up. just wondering why it went up. thanks

 

[S1ngram]

I had a similar experience just recently. I don't know why it happened, but it made me happy since I'm trying to lower my TA. In my case, we have had lots of rain...I don't know if that altered pH but I doubt it. Over Father's day weekend, we had a lot of kids in the pool spashing around. That's probably what did it.

 

[CageAnimial135]

I've seen people leave their covers on and 5 days and have algae when in covered. I build a solar panel for mine and attached to my roof and ran all my irrigation line off my pool pump which I included waste lines for when i don't have it running. Because there is always water in those line that you don't want coming back to your pool so I usually flush it for 15 seconds

 

[pookiesunshine]

S1, yes, forgot we had a good bit of rain. had to lower water level about an inch. antacid rain? lol.

 

[Richard320]

S1, yes, forgot we had a good bit of rain. had to lower water level about an inch. antacid rain? lol.

Rain pelting the pool surface aerates it well, which can cause pH to rise.

 

[pookiesunshine]

Richard, yes, but solar cover was on when it rained.