CYA level jumped high, but only using liquid chlorine.

[whotheguy]

Hey all. first I would like to say this forum bailed me out when I bought a house that had a green pool. I learned a lot by being a lurker, but I was well informed. Thank you.

Here's my current problem. About 3 months ago I had to turn the green pool around. Then I had to battle a very high CYA level, drained way more than I should of and got very low CYA levels, almost nothing. Brought the level back up to about 30 ppm slowly using conditioner. This was all over the coarse of about a week. Pool was clear and clean, only have to balance it about once a week and add chlorine a couple times a week-I live in the heat. So for the past couple months all has been good. About 3 days ago I tested my CYA level for about the 3rd time since adjusting it. It tested high, like 70 ppm. Remember, it was always around 30 ppm for weeks and weeks. I tested it again yesterday, and I'm about 70-80 ppm. I use the Taylor K-2006 kit. I also DO NOT use tabs or anything that has Dichlor or Trichlor in it. I'm strictly liquid, and no powdered shock.

So there's my problem, I don't know how it's going up, but it is. Only chemicals I put in the pool are, unbalanced liquid chlorine, muratic acid and baking soda. I'll use a clarifier every once in a while.

Thanks in advance for any help.

Robert

[Watermom]

What is your volume and how much CYA did you put in? (I assume it was the granular?)

[whotheguy]

15K and I don't remember exactly how much because I added, ran pump 12 hours, tested and then repeated until I got around 30 ppm. If I had to guess I would say about 3 lbs. And yes, granular.

[Watermom]

How did you add it? Through the skimmer?

[whotheguy]

I did add it through the skimmer.

[Watermom]

So, here is what I think happened.

Even though you thought you had nearly none after you did your partial drain, you may have had almost 30ppm since any amounts less than that won't register on the test.

CYA takes a long time to dissolve -- like 4-5 days or even a week. So, each day when you tested, the CYA that you had added the day or so before had not fully dissolved and thus wasn't being picked up yet on the test. So, you added more. You are guessing that you added about 3 lbs. If it was 3 lbs., that would have added about 25 more. But, since you are only guessing, it could have been more. Maybe 4 lbs or whatever.

When you add it altogether --- the maybe 30 you already had in there + the maybe 25-40 you added, it could be around 70ish or so now.

At any rate, even if it is 70 or 80 now, that's ok. Just run your chlorine levels at the needed levels and you'll be fine. More info about the relationship between CYA levels and needed chlorine levels can be found here:> http://pool9.net/cl-cya/

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Hope this helps. Welcome to the Pool Forum, by the way!