Depends on the kind of rain you're getting. A gentle, steady 'farmers' rain' won't have much impact. The sort of gully washers we've been having here in eastern PA are increasing my pH as a result of aeration. TA has remained steady at 90, pH rose from 7.6 to 7.8 overnight. We had 4" of rain within an hour. You can imagine how that pounded the water surface.
I believe the size of your pool is significant as well. A 2" rain into a 36" ABG will have more impact than the same rain on a large pool with a deep diving end.
By far, the greatest impact is if your decking does not drain the pool properly and runoff is allowed to enter the pool.....that is usually very big trouble.
The sort of gully washers we've been having here in eastern PA are increasing my pH as a result of aeration. TA has remained steady at 90, pH rose from 7.6 to 7.8 overnight. We had 4" of rain within an hour. You can imagine how that pounded the water surface.
I thought rain was acidic, thereby reducing pH....but then the raindrops aerate the water, thereby increasing pH...so it would basically be a wash (no pun intended) for the most part. Is any of this assumption correct?
A heavy rain on an uncovered pool will aerate a lot, enough to counteract the acidic rain. Gentler rain and covers limit this effect and you might see a drop. I didn't get my cover until after the major rains were over so I don't have any personal experience to back that up, however.
--paulr
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Welcome to TFP! For a wealth of pool care information please check out our free Pool School. If you are in need of specific help then we encourage you to Register and ask us here in the forum!