High CYA Level

[dagall]

I put the Pool Wizard in the pool three days ago and it is AMAZING, the pool is absolutely beautiful.
My question is with using so much shock and chlorine pucks to try to get rid of a little algea, I have increased my CYA level to over 100. With the wizard I am to maintain a free chlorine level of .5 to .8. With the high CYA should I keep the level this low or increase it?

[dagall]

Anybody?

[Guest]

High Cyanuric acid will come down eventually from Sunlight. You could also dump a couple feet of water and add fresh to dilute it down. A good range is between 50-100 so I wouldn't panic about it.

[chem geek]

Next time you need to shock the pool to get rid of algae, use chlorinating liquid or unscented bleach so that you don't increase the CYA level (or you can use Cal-Hypo, but that increases Calcium Hardness).

If you didn't have copper from the pool wizard, you'd need an FC of around 7.5 ppm to keep away algae with a CYA of 100 ppm. I don't know what level you need with the Pool Wizard, but for sanitation with a CYA of 100 ppm I wouldn't go below 1 ppm, just to be on the safe side. Just remember that the amount of disinfecting chlorine (hypochlorous acid) in the pool is proportional to the FC/CYA ratio so 1 ppm FC with 100 ppm CYA is really quite a low level of chlorine -- the same as 0.2 ppm FC with 20 ppm, for example.

The CYA level does not generally break down from sunlight. CYA does seem to degrade slowly, but it's quite slow -- many people report it lasting an entire season with no discernible drop (even using only unstabilized chlorine) unless they are diluting their water via backwashing their filter.

Richard