adding calcium hardness increaser


Apr 26, 2014
Bakersfield, California
Drained and refilled pool with 7 month old dark gray plaster (colorscapes).
I have added liquid chlorine, CYA and MA. These are my test results:

FC= 0.5
PH= 7.6
TA= 80
CH= 100
CYA= 20

I am concerned as to how to add calcium hardness increaser without etching plaster finish.
Can i dilute CH increaser in bucket of warm water before adding to pool? CH increaser instructions state just to broadcast in pool with pump running without premixing in bucket of water.

Also should PH be a certain level before doing this?


TFP Expert
Mar 2, 2011
Broadcasting and brushing works OK as long as you brush quickly and thoroughly. If the calcium sits for too long, it can stick to the bottom. The colder the water, the faster the calcium can stick.

Premixing in a bucket also works. I would recommend that you do not exceed 2.5 pounds of calcium chloride per gallon of water. Also, don't use warm water in the bucket; just use pool water. Brush after adding the calcium by dilution.

Your pH is fine for adding the calcium.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
The issue with pre-mixing in a bucket is that it gets quite hot as it dissolves. If you are aware of that issue and use lots of water per pound of calcium it isn't a big deal, but if it catches you unaware you can burn yourself.