Low pH at opening, cause?

[linuxninja00]

Hello fellow TFPers,

Just opened my pool today and my first readings were:

FC - 0
pH - 6.8
TA - 40
CH - 125
CYA - 20 (water was 60 degrees and I didn't bring it to room temp, so maybe inaccurate)
Water Temp - 60

I closed the pool with a pH around 7.3 I believe. This is the first year I've had low pH after closing and opening. Only change was I changed my solid cover for a lighter weight solid cover that has a drain. Pros and cons with that cover. For one, it was much easier to remove due to weight, however with the cover drain I did get lots of pollen and a little algae started forming. None of this is really an issue for me as I've been TFPing for years so my pH is now at 7.2 and I'm SLAMing that algae. Was just curious of what might cause the pH to drop over winter. Pool was clean minus a few leaves that I missed. Few being 2 or 3. I sure did like opening the pool with the previous cover to 5 FC, but man it was a beast. Swear that thing weighed 300 pounds folded up.

 

[wireform]

The TA goes hand in hand with the PH. Your TA is low so it'll effect the ph too.

 

[linuxninja00]

Thanks. My TA is definitely lower at open as well, it was in the recommended range. I assume that is just due to the rain draining through the cover, me pumping it out and more rain coming in .