Managing high CH in my SW pool

[acroy]

I have high CH – incoming water around 200ppm and lots of evaporation. Last year it got to around 650 , doing my best to manage it with good pH control. Partial drain/refill last month got it under 400. Drain/refill is several hundred dollars between water, borates, acid, salt….

See below for chemistry and please comment if any improvements I can make! (numbers from a ‘good’ test kit!)

FC = 5
pH = 7.7
TA = 80
CH = 380 (current)
CYA = 75
Salt = 3500
Borates = 50
Temp = 70 and rising

Looking good? This gives me a CSI of -0.26. As temp goes up CSI will move closer to zero. As CH goes up (and it will!) it will also drive CSI up.

As long as I keep pH and TA where they belong, and CSI slightly negative, it should not be an issue as CH increases, correct?

 

[JasonLion]

You have the right idea. You can let the CSI go up to +0.3 if you need to as CH gets higher. The main thing to watch for is that PH tends to go up when you aren't looking. The higher CSI gets, the more sensitive you are to PH going up. With CH at 380 this isn't much of an issue, but with CH around 650 it becomes something to watch out for.

Next spring you might want to check to see if reverse osmosis (RO) treatments are available in your area. RO is a way to get the CH (and other stuff) out of the water without draining.

 

[acroy]

Good to know I'm on the right track - thanks!