I have always had CH around 400. I am constantly battling rising pH (we have a hot tub with a waterfall and two bubblers). Just trying to get my pool ready and ran my usual barrage of tests and decided to test my fill water. Surprisingly my fill water tested CH at like 50!!!!! How can the CH in the pool be so much higher? I will admit one thing and maybe it did or didn't contribute. We are doing some privacy panels and other landscaping so I measured my pool and it seems by my math that my pool is about 10,000 less than the builder told me. So for the past several years I have been making all of my adjustments, chemical additions, salt, etc based on 35,000 when my pool is actually closer to 25,000 gallons. I know the pool school says 400 is in the acceptable range for a gunite pool with SWG, but now i'm curious as to why the difference and what i should do?
Calcium Hardness doesn't match fill water?
- Thread starter bigwillokc
- Start date
How long has that water been in the pool? Evaporation can cause increased calcium and salt because the water goes but those chemicals stay behind.
Ever use granular shock which may contain calcium?
Maddie
Ever use granular shock which may contain calcium?
Maddie
Every time you add tap water you are adding CH. That water evaporates leaving the CH behind.
You don't have to do anything. 400ppm is totally acceptable for a plaster pool. Just keep an eye on it.
- Mar 5, 2020
- 2,947
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
CH 400 is actually pretty good. That will allow you to decrease your TA to address your pH-rise, without reducing your CSI too much (water with CSI below -0.3 is starting to get more corrosive for plaster surfaces).
What is your current TA? Best to post a full set of test results.
What is your current TA? Best to post a full set of test results.
Test results from today:
FC - 1.8
CC - 0
pH - 7.4
TA - 70
CH - 400
CYA - 60
SALT - 2400
BOR - 15
CSI - (-0.59)
TEMP - 58
FC - 1.8
CC - 0
pH - 7.4
TA - 70
CH - 400
CYA - 60
SALT - 2400
BOR - 15
CSI - (-0.59)
TEMP - 58
- Mar 5, 2020
- 2,947
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
Your CSI is quite low due to the still cold water. Allow your pH to be higher to compensate for that. That should also help your pH-drift. Target a pH more around 7.8, only add acid once you reach 8. The lower your pH, the faster CO2 outgasses, and the faster the pH-drift.
And get your FC higher, you are a bit low.
And get your FC higher, you are a bit low.
- May 3, 2014
- 58,302
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
- May 3, 2014
- 58,302
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
I’ve often wondered the same thing. In Houston we have extremely hard water. U can see it on fixtures and in the pipes. U would figure HIGH Ca. However when I test for Ca in my fill water I get 50 ppm. I’ve done this like 5 times. I think the issue here is our water is high in CaCARBONATE with the Carbonate being the high part. It must be because my CH drops throughout the year and I’m adding CaCl not constantly but fairly often. You may have same issue up there.
We had a cold front come in it was in the 70's earlier this week and pH was 8.4 so i added a gallon of MA.
Ah, Yeah i can turn off the bubblers but i can't do anything about the spa spillover. If the pool pumps are on, it goes through the hot tub and spills over. The only time the spillway isn't active is when its set to hot tub only
- May 3, 2014
- 58,302
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Not correct. You can set up a Spillway function and schedule it. Depending on your plumbing, you would either have to turn off the valve for your make up water to the spa side or adjust the valve actuator on the return side so it goes either full Spa or Pool return.