Would you bother tinkering (calcium)?


Well-known member
Apr 15, 2014
Livermore, CA
Pool Size
Liquid Chlorine
Hey Y'all,
I've been lowering my TA. Somehow, after vaca it was at 120. Got it down to 80 with my test just now. I tested my CH as well. CH ~300 (last was month 275). So, I'll still use 275. My fill water is ~100.

My TA usually seems to be happy and/or was resting at about 90 in May, then crept to 100 come June. I left it alone b/c my CSI was fine and was managing my pH just fine. With my Wet Edge Satin Matrix, it does much better and I see a slow pH rise vs. my prior plaster back pre-12/2018; so the TA of 100 was manageable. Anyhow, I lowered it again to TA 80 to "reset" so to speak. My CH also seems to hover around 275 (or at least that is what my eyes seem to register with the TF-100 drop test).

So, today I was testing out water scenarios using the Pool Math app in prep for the winter when pool water drops to 55. We never close our pool, and do occasionally jump in in the winter. So, I was trying out various scenarios with my pH 7.2-7.8 and TA at 80. And, this was with a CH of 275. The CSI seems to show me that I can't let my pH drop below 7.5-7.6 or else it is unhappy.

I went to Leslie's to corroborate my data since my store uses the fancy digital computerized testing machine. Numbers differ with mine. The sales guy said the calcium at least could be 20% different (I think he said percent not points). So here are Leslie's and mine.

FC 7
CC 0.5
pH 7.5
TA 80
CH 275-300 (approximately)
CYA 40
No salt but I just throw in a number of 500 based on all of our swimming, sweating, etc. And, I thought I read at TFP that even non-swg users should enter some number in the Salt section for his/her testing.
Temp 85

FC 6.15
Total Chlor 6.55
pH 7.7
TA 89
CH 192
CYA 39
(I am not going to list all their other baloney numbers re: metals, phosphates, blah blah blah)

My gut is telling me to add a tiny bit of Calcium. If I wanted to bring to 350, even if my CH is 300, it shows to add 141 oz. I was thinking of only starting with adding 30 oz. What do you all think? Tinker or leave good enough alone. I just have a feeling with the winter rain it may lower the CH, and my fill water is only CH 100. I use a solar cover so I am not adding water that often.
Last edited:


Gold Supporter
Oct 4, 2020
Fort Worth, Texas
Pool Size
Salt Water Generator
SWG Type
CircuPool RJ-60 Plus
The only thing I’d do is stop going to the pool store. Inviting them to give you conflicting data points is a recipe for trouble.
Otherwise - raising your CH a bit wouldn’t hurt, but also isn’t totally necessary.
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