CYA test help...Am I doing it wrong?

[BigDave]

How much dichlor have you used?

[NannyAng]

For the past 3 days, I've been adding approximately 1 ounce (2 tablespoons) every night plus another 1/2 ounce mid day before the kids swim. So a total of approximately 6 ounces so far.

[singingpond]

Not sure if you saw my response, in your other thread on the same topic:

http://www.poolforum.com/pf2/showthr...A-testing-help

I'll repeat the relevant comments (in case the other thread disappears):

I believe that the ratio of ingredients in dichlor is such that for every 10 ppm FC (free chlorine) you add (via dichlor), you also add 9 ppm CYA. The free chlorine gets used up on an ongoing basis, one way or another, but the CYA remains in the water. If you know how much dichlor you've put in, it should be possible to estimate your current CYA level, and also to estimate how much total dichlor you'd have to put in to reach 30+ ppm of CYA. Looking at it another way, to reach 30 ppm of CYA, you'd have to put in enough dichlor (total) for about 35 ppm FC. If you look at poolcalculator.com (putting in 1000 gallons for pool volume) and ask for FC to go from 0 up to 35, that seems to call for about 8 oz. total of dichlor. I think that's in the ballpark anyway (I'm new here on the forum, so take these estimates with a grain of salt accordingly).

[BigDave]

6 oz. dichlor will add about 23 ppm CYA to 1000 gallons. It'll take another two oz. before it can be measured.