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