CYA testing help

[NannyAng]

I use the HTH 6 way test kit.

I have a smaller Intex AG pool that holds approximately 1000 gallons. Its been set up for about 3 weeks and I've been following the super simple pool chemistry recipe from pool doc. I've been using 7.86% bleach. I test Cl and pH every morning and the readings have been steady at 2-3ppm Cl and 7.8-7.9 pH. On days I'm going to have 2 or 3 toddlers swimming, I test the water again before they swim to make sure there's sufficient levles to handle any accidents they may have. The second tests have shown Cl at almost 0 every time. I tried testing CYA level but the water sample never turns cloudy after adding the test cbemical like it should. I now understand that this means my CYA levels are just too low for the test to read. I began using dichlor shock 2 days ago, I know it contains stabilizer also. My question is this: how long should it take for the dichlor to add enough stabilizer to the water to bring my CYA level up high enough to test for it. Also, do you suggest purchasing a seperate stabilizer to bring CYA up or just rely on the dichlor to give me the stabilizer I need. If you do suggest a stabilizer, would HTH stabilizer and conditioner from Walmart be ok to use. (Since its in stock, affordable, and I don't have enough time left in the summer season to have something shipped to me)

[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.

[chem geek]

Adding 8 ounces of Dichlor to 1000 gallons would add 33 ppm FC and 30 ppm CYA. The HTH Stabilizer & Conditioner from Walmart is OK to use as it is nearly pure CYA, but be aware that it will take time to dissolve. Put it in a thin sock or panty hose and hang over a return with the pump running or put it into a small cloth bag in the skimmer (but don't completely plug up the skimmer). With water flow, it should dissolve within one day. Though it is convenient to just add it to the skimmer to get caught in the filter, it will then take many days to fully dissolve since the flow rate through the filter (depending on the filter's area) is very slow.

[NannyAng]

I've finally gotten my CYA level up to 33. My questions now are these: 1. What is a healthy level of CYA to maintain? 2. Does stablizer disintigrate on its own if I stop using dichlor and only use bleach? 3. Once I reach that healthy level, should I switch back to only using bleach, or maybe bleach 5 days out of the week and dichlor the other 2?

[Watermom]

1. For most pools, a CYA reading of around 50 is what we recommend.
2. CYA levels don't really change much during the summer but sometimes it does biodegrade over the winter. When it does, you have a huge chlorine demand upon opening.
3. Once you get your CYA where you want it, just switch to bleach.