CYA testing help

[singingpond]

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).

How much dichlor have you been putting in daily, and how are your chlorine numbers looking? Are you testing FC, or just using an OTO test kit (the one that turns yellow) to estimate your total chlorine level? EDIT -- just re-read your post, and see you are using HTH 6-way kit, which doesn't do separate FC test END EDIT. Have you noticed your pH starting to drop (a consequence of adding dichlor)?

I'm not an expert by any means (I also own a ~1000 gal pool, and just joined this forum a few weeks ago), so I don't have much to say about the HTH stabilizer. I know that people here seem to recommend against most of these products (bringing unknown ingredients into the pool chemistry mix), and I've never tried the stuff myself, so can't speak from experience.