CH question

[whataboy]

Last month CH was 325
Last week CH was 350
Today CH is 375 (tested twice with same results)
What's causing it to rise? Pool was re-plastered on May 2nd and all my numbers have been in range but now CH is rising
Added couple trichlor tabs to bring up CYA few weeks ago but it shouldn't have anything to do with rising CH rising.

Numbers today:

FC-not checked cause pool still in full sunlight but normally 3.5 to 4 before adding bleach at sunset
CC-0
PH-7.6
TA-80
CH-375
CYA-40
BORATE-45

Water is crystal clear

 

[zea3]

Don't let the pH go any higher. Try and keep it around 7.2 Have you tested the CH of your fill water? If you are topping off with high CH fill water that will cause a rise in CH in the pool.

 

[whataboy]

Fill water CH is 100. Been topping off couple times a week cause its 100 degrees here with lots of sun and no rain for past month.

 

[whataboy]

Don't let the pH go any higher. Try and keep it around 7.2 Have you tested the CH of your fill water? If you are topping off with high CH fill water that will cause a rise in CH in the pool.

Just out of curiosity how does lowering PH help rising CH? Thanks
The CH in my fill water is 100

 

[Richard320]

When water evaporates, CH doesn't. It stays behind. You CH rise sounds perfectly normal to me.

The pH has nothing to do with CH. But pH & TA & CH in the wrong combination can lead to Calcium Scale formation. That's grow-you-own sandpaper right on the walls. It'll give you roadrash just banging and elbow or knee against it. If you plug your numbers into poolmath it will give you CSI. See what happens to it if you change the pH, TA, and/or CH.