Adding Calcium

[Tommygarry1]

Hi all. Anyone ever add Calcium and the test doesn't budge? I added 12 lbs of Calcium to my pool which according to pool math should raise it about 46. I did this at a 250 reading. I tested a few times after and it was 275 once only to read 250 again. I added another 12 lbs and it went up to 275 again...then back to testing at 250. What gives ? I ultimately want it above 350 where it should be according to pool school in plaster pools. Thx

 

[HermanTX]

If you are using the 10ml pool sample, each drop is 25ppm so you can be +/-25ppm on any test.
Try the 25ml pool sample where each drop is 10ppm.
The R-0010 is then 20 drops and the R-0011L is 5 drops. Then the number drops of R-0012 is x by 10ppm. The 25ml sample uses more drops of each reagent but provides some more accuracy.

 

[Tommygarry1]

Just tried that after I posted ! I got 290. Much better way to do it.

 

[jesse-99]

How long were you waiting to test after adding the Calcium Chloride? It's possible the test sample just didn't have a good mixture yet if you took the test sample too soon after the addition?