Advice on Calcium Hardness


Bronze Supporter
Jun 2, 2016
My calcium hardness is at 240 but I've noticed websites suggesting that CH should be 175 - 225 although TFP is suggesting an ideal range of 350 - 500 which is much higher. Why would there be such a difference, what number should I use (I don't want to exchange water if its too high), and what is the target number for most of you? Thanks.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
TFP calcium recommendations are made looking not just at the CH requirements of your plaster but also at the overall water balance as measured by the Calcium Scaling Index - CSI. We have found a higher CH level provides the needed balance .

You need to use PoolMath to calculate your CSI and see if your CH level works for your water chemistry.

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