Question on rain and pH levels

[Molson]

My pool has been open since late April. No one has been in it yet, still waiting for it to warm up. Temp at ~74 now.
I tested my water a few weeks ago and the pH was 7.5 . Bromine levels have been fine (Have brominator). I tested the pH a couple days ago and it was low, 7.1/7.2ish. We have had a lot of rain lately. Would that be the cause of the low pH? I try to get the cover off and vac at least once a week to keep it clean. I bought a box of borax, but I think I'll need 2 to get it back to 7.5 range.

 

[giulietta1]

Rain does tend to be acidic, so that's certainly a possibility for the cause of your low pH. What are your other test levels? It would help to know the TA, especially. If your TA is low, you might want to use soda ash (washing soda) instead of borax. Some (not all) bromine sources are acidic and tend to cause depletion of the TA and subsequent dropping of the pH.

I am curious; why bromine? (If you explained it in some other thread, just direct me there.

 

[Molson]

Its an easy answer. Bromine cause thats the way it was when I bought the house in November.

TA last checked was 85. You're right, I should use some Washing soda instead.