Do I Really Need to Worry About Low CH?

Team Mel

Member
Jun 22, 2019
6
Portage, Michigan
Hello! New here and recently switched over to the TFP method after two years of using a frog system in a 30k gal gunite/plaster pool. I drained and refilled 3/4 of the pool a few weeks ago to lower our CYA build up and haven't had to SLAM. The TA of our tap water is 270 so I've been bringing it with acid and aeration over the past couple of weeks. My question is regarding CH, which I was previously unaware I needed to be concerned with at all. Do I really need to worry about bringing it up? The PH has been holding, the pool is crystal clear, and I'm only adding 2.0 or less CL per day to maintain 5.0 FC.

FC: 5.0
CC: 0
PH: 7.4
TA: 190
CH: 200
CYA: 40
Temp: 84
[Tested with k-2006 Taylor kit]
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
30,038
Laughlin, NV
CH is necessary to protect your plaster finish. You do not want the water to become aggressive and remove calcium from your plaster.

I assume with your TA that high, that you have high TA fill water?

Right now, you are OK. But if your TA is dropped to near 100, you should raise your CH to 300 ppm.

Be sure to have your CH near 350 when you winterize your pool. The cold water makes it very aggressive.
 

Team Mel

Member
Jun 22, 2019
6
Portage, Michigan
CH is necessary to protect your plaster finish. You do not want the water to become aggressive and remove calcium from your plaster.

I assume with your TA that high, that you have high TA fill water?

Right now, you are OK. But if your TA is dropped to near 100, you should raise your CH to 300 ppm.

Be sure to have your CH near 350 when you winterize your pool. The cold water makes it very aggressive.
Yes, the fill water TA is 270. I intend to drop the TA to as close to 100 as possible. Thanks!