Calcium Hardness and Total Alkalinity Question


Silver Supporter
Mar 8, 2017
Coopersburg, PA

I have been using TFP and TF Test Kits for three seasons. This is our fourth year with a pool and my fourth year using the TFP Process for balancing our water. I am in the midst of SLAMming since opening the pool last Saturday, May 16th. Here are my current levels:

FC: 13
CC: 0
TC: 13
CH: 50
TA: 100
pH: 7.7 (may not be accurate since I've been SLAMming)
CYA: 50

I just added liquid chlorine to bring the FC level up to the recommended SLAM shock level of 20 for a pool with a CYA reading of 50.

My question is on calcium hardness and total alkalinity. We have a vinyl in-ground pool. Do I need to get my calcium hardness up higher? I see the recommended levels for my type of pool are 50-550. Also, does my total alkalinity need to come down closer to 80? My TF Test Kit instructions say I should be around 100 but the TFP recommended levels page says 60-80 is ideal and 80-90 is an acceptable maximum level.

Any input would be appreciated. Thank you.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Your CH is fine for vinyl pool with no heater..

Your TA is ok and will come down as you lower your pH. No reason to force it.

What is pH, TA & CH of your fill water?
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Silver Supporter
Mar 8, 2017
Coopersburg, PA
Thank you for your reply.

I haven't added any significant amount of new water to our pool in three years. I also have not tested the well water we would fill with for those levels (pH, TA and CH). We have a mesh cover so snow and rain get added to the pool throughout the winter.

I'm considering adding a heater - what should I keep in mind with respect to CH if I do add a heater?