Calcium Hardness , Vinyl Pool Liners and Pool Math

rbuckels

New member
Jul 22, 2015
1
Brookhaven, MS
Hi, this is my first post.

I am opening my pool with the help of the TFP Pool Math mobile app and also by reading TFP forums - but I have some questions. I have recently read many posts from TFP experts that if you have a vinyl liner it doesn't matter what your calcium hardness is. If I have understood this correctly, why doesn't Pool Math take this into consideration since I have input "vinyl pool" in My Pool Setup? In other words, why doesn't Pool Math either not include the CH measurement or "flag" and warn you with a comment to disregard CH when you have a vinyl liner?

Anyways, I bought CaCL from the local pool store to adjust from 40 CH to 300ppm per Pool Math's direction- this was before reading the forum. Are there any benefits at all to raising my CH in a vinyl pool? Are there any harmful effects of low CH in a vinyl liner pool - will a low CH harm my pool equipment?

Thanks so much for any advice you can give,
Roy
 
Last edited:

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
39,695
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Welcome to the forum!
New vinyl liners are not made with calcium in them. So no calcium is needed in the water to protect it. The Recommended Levels show a range from 50 ppm to 550 ppm as the ideal range. 50 ppm is normally what is needed to keep the pool water from foaming.
If you have a heater, most manufacturers recommend 200 ppm CH in the water. That is supposed to protect the heat exchanger. That is based on steam boiler technology. So it is questionable if the CH is needed, but TFPC does not have any science to back up not recommending some calcium in the water if you have a heater, so we do recommend that, even in a vinyl liner pool.
I suggest you read ABC's of Pool Water Chemistry.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
39,695
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
I see you mentioned in the app. In the app, for a vinyl pool, the range for CH as shown on the overview page is 0-650 ppm.