Do you have to buy CYA?

[rastoma]

Since I'm not using the powdered 6 in one stuff any more, will I have to get CYA eventually or does it maintain itself if everything else is kept in check?

Is CYA present in tap water? Just wondering if the constant topping off of my small pool will lower the CYA. It hasn't yet but just wondering.

[Spensar]

CYA is an additive that does not come in tap water. It does not go away, so the amount you add cumulates. When you backwash, vac to drain, etc. it removes some and when you add water it gets diluted a bit.

If it is in the chemical (6 in1) that you are using, it is being added. Don't know what rate it is being added at, but you can get a test kit or bring your water to some pool stores to get it checked. If using a store, I suggest going to a couple or go back a couple of days apart to ensure they have the same measurement. The stores can and do mess up tests sometimes. I believe this forum recommends a typical range for home pools from 30 to 50 ppm.

[rastoma]

I haven't added any chemicals in a week other than bleach and borax and I've had to top up the pool a few times (it's a small pool) and CYA has gone from 50 to 60 after a week. So if it's not in tap water how has it increased?

[duraleigh]

The test is subjective. One person will read 50, another 60. It only increases if you add it to your pool.

[Watermom]

Also, it is slow dissolving. It takes about a week for it to totally dissolve, so it may just be that when you tested and got the cya reading of 50, it all hadn't yet dissolved.