Refilling pool - need help avoiding hard water concerns

CoachTom

Gold Supporter
Dec 14, 2023
31
Safety Harbor, Florida
Pool Size
15000
Surface
Plaster
Chlorine
Liquid Chlorine
We are refilling our 15000 gallon pool after having some work done. During the work, we did get quite a lot of water back into the pool as we’ve had a ton of rain here in central Florida the past month or more. That led to quite a bit of algae and even a bunch of tadpoles growing in the pool. The pool has been emptied now, dirt vacuumed out, tadpoles are gone.

The interior also has a bit of scale build up that we are trying to remove through careful pressure washing and possible acid washing. My pool builder is doing the work for now.

Anyway, for the refill I want to make sure I set it up correctly. I tested my refill water:

FC - .5
CC - 4.0
pH- 8.5+ (very red)
TA - 160
CYA - 0
Temp - approx 60F (need to get a good thermometer on this still)
CSI - approx .62

Any thoughts or concerns with the refill? I assume I will need to start with a shock and get chlorine back up to correct levels. I’ve always had trouble maintaining pH levels as it seems to go up very quickly and I’m adding muriatic acid a few times per week.

Do I need to test for anything else at the pool store or do I have enough info from my existing tests? Is hard water a concern? Ive been told it’s a concern but not sure if the CH test is enough to know for sure.

Thanks for all the help and input!
Tom
 
Your CH test is enough and more accurate than pool store. But you didn't list the CH of your fill water. For a plaster pool, you want at least 200-250 CH. What is your fill CH?

The need for acid is because of the high TA in your fill water.

Because of the high TA and CSI, I'd read through these...
 
Sorry!
CH - 150

I’ve read those posts previously and can keep my levels down with regular addition of acid. Was hoping to get it in better control. I’m not adding water very often so I can’t figure out why it goes up so quickly on its own.
 
The fill water results in your post are different from those in your signature.
Not sure which are more accurate.
Be sure to clean your testing vials with rubbing alcohol.

Your pH will rise pretty quickly until your TA gets down to about 60-70.
 
TA has always risen quickly. The fill water was just tested this morning. We had new water lines installed in my neighborhood which might explain the difference in my old fill water tests. In the past, getting pH down to TA down to 60-70 didn’t keep pH from rising fast enough to need acid twice a week.
 
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