Advice on my "Plan" for CYA too High


Well-known member
Aug 1, 2020

Water was crystal clear until the past fews days when it started to get a little bit cloudy, so I ran a full test with my Taylor test kit....the pH was taken before I added 2 bags of powder shock, the rest was after.

pH 7.4
TA 150
Calcium 450
FC 8
CYA 85
Water temp 84

I have been addressing my high TA by slowing adding muriatic acid to bring the pH to 7.2, then keeping my sun ledge bubbler running to bring the pH back up to 7.6-7.8, and repeating the process. I started with a TA of 200 about 3 weeks ago, so I'm making progress.

I also plan to purge some of the water. I have an autocover with an overflow drain + a pot filler that I can add tap water to. In order to drop the CYA, calcium, and additionally the TA, I plan to run tap water to make the pool slowly overflow until I get the CYA down to close to 30. I will add either liquid or powder shock on a routine (daily if needed) basis to keep my FC up.

Does that sound right?


Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
Rancho Cucamonga, CA
Pool Size
Salt Water Generator
SWG Type
CircuPool RJ-45
Exchanging water as you describe may or may not be efficient based on several factors including fill/pool water temps, water density, and fill/drain locations. There is a process called a "No Drain Water Exchange" that may assist you. It may be more efficient to use a submersible pump and fill hose.

When determining CYA levels, round up. Your CYA is 90.

Keep an eye on your CH if you're using cal-hypo. The chlorine in cal-hypo is stabilized by calcium which will increase CH levels rapidly. If your chlorinator uses tablets, don't use it. Tablets will increase CYA. Consider a salt water chlorine generator (SWG). SWGs work with higher CYA levels and wouldn't need to drain much, if any, water.

Your plan on lowering TA is sounds good and seems to be working.

Best of luck!
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