low cya

[gettinthesplash]

I have a 24' above ground pool. My cya is too low to be measured with my Taylor test kit. And I have a feeling my chlorine is disappearing too fast. I use liquid bleach (12%). I test chlorine levels at least every other morning, a lot of times every morning, and I normally get .5 ppm or 0. Then I add at least a quart. I have some chlorinating granules. Wondering if I can use that for a little to bring the cya up or do I just need to go get some stabilizer? These are the ingredients: trichloro-s-triazinatrione 71.8%, boron sodium oxide pentahydrate 8%, other (clarifier/filtration enhancer/sunlight protector) 20% I have not had any problems with algae this year, and I don't want to start.

[Admin note: trichloro-s-triazinatrione = trichlor; boron sodium oxide pentahydrate = borax or "5 mol borax". The odd name is used to try to keep people from thinking, "Oh, that's just borax!". ]

[aylad]

Hi,

You are right that the CYA is too low, if you can't measure it with your TAylor kit, and that's one reason why you're not able to keep chlorine in the pool. If you're consistently getting chlorine levels of .5 or 0, then you're lucky you haven't gotten an algae bloom yet. In fact, I would probably go ahead and shock the pool just to make sure you don't have one brewing, because a nascent algae bloom can consume large amounts of chlorine, as well. YOu can tell the difference by testing for chlorine at night after sundown and again in the morning before the sun is on the pool. If you've lost chlorine overnight, then you're working on a case of algae. If not, then you just need to raise your CYA,.

You can use trichlor to chlorinate with, and will raise your CYA at the same time, as long as your pH isn't too low. Trichlor will tend to drive your pH down, so watch it and make sure that it stays above 7.0 at all times. If you can do that and maintain chlorine in the pool, there's nothing wrong with it--but if you're still having trouble keeping chlorine in the pool, I would just add the stabilizer itself and continue with your bleach. If you decide to add CYA by itself, you can put it into the skimmer and let it dissolve in your filter, but don't backwash or test for it for at least a week because it takes awhile to register Or you can put it in an old sock and hang it in front of a return and it will dissolve that way.

Janet