CH level questions…

jdchess

New member
Jun 18, 2023
4
Southeastern NC
Pool Size
10000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-9)
I’m fairly new pool owner in southeastern NC. I have an older 10000 gallon fiberglass pool with SWG. My CH is testing really low. Initial test was 30. I double checked the test and I also tested my fill water. I’m on a well and it showed a CH of only 10ppm. Again, I double checked the test. Same result. From what I’m reading online, levels this low seem somewhat unlikely. Is this true?

I’m using a Taylor kit. I’m using the 25mL sample, adding the initial 20 drops and swirling, then adding the 5 indicator drops and swirling. Sample turns pink (not red). I then add the last chem one drop at a time swirling between each drop. It only takes one drop to turn fill water baby blue. The reagents have an exp date of 10/24.

I feel like I’m doing everything correctly. Likelihood that the low CH is correct?
 
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Modern fiberglass pools do not need calcium in the water.

You can check with your pool manufacturer for their recommendation.

If you have a gas heater it requires 200ppm of calcium.

 
I prefer the 10 ml sample size with the 10 drops of #10, 3 drops of #11, then count the drops of #12. Some areas do have low CH. The TFP minimum CH number is a safety catch-all for various reasons and pool scenarios. Unless you have waterline tile or equipment that requires a minimum CH level, low is okay. The only other benefit to maintaining "some" CH level (i.e. 100 or so) might be possibly reducing the likelihood of certain types of staining, but use your own good judgement.
 
Thank you for the replies. It is an older fiberglass pool…about 30-35 years old. No clue who the manufacturer was.

I was under the impression that I still needed to get the CH up to normal range, so I have already added enough calcium chloride to get the CH up to about 350 which is what the PoolMath app shows as the bottom of the ideal range. I did this yesterday afternoon and was about to retest.

While maybe not necessary for fiberglass, will bringing it up to about 350 cause any problems? Do I need to drain some and refill to lower? With 10ppm fill water, I suppose this wouldn’t be difficult.

Guess I jumped the gun a little. 😐
 
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No, having the CH will not cause any problems.