Quote Originally Posted by haze_1956
Ok, I am a bit confused now, so I am in need of the wisdom of the many !

DId the following to 38000 gallon gunite pool:

7-26 Checked pool, no hardness reading, just turned sample a little yellowish
7-29 Added 50 pounds of Calcium Chloride flakes
7-31 Checked and still getting only a little yellow in sample
8-1 Added 100 more pounds of Calcium Choride flakes
8-3 Checked and got a nice reddish/purple in sample, tested out at 600 on Hardness

This was a bit high, but Cya is 90 -100 anyway, so figured drain and refilling in a couple weeks would take care of both problems

8-22 Stopped by to check pool and again reading no hardness, test turns a little yellowish not red/purple at all.

Can anyone tell me what happened ?

Did the plaster reabsorb the Calcium?
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What test kit are you using....The aquachem 6 way has an issue with the calcium hardness test that has been discussed previously in the forum....sounds like the one you are using since you said you got a yellow color