Cya -0-

[rlanthony]

My cya is -0-. It was about 35. Can' keep cl- in the pool. I'm thinking to use pucks until the cya levels come up. Plus black algae spots, not major but an indicator of chronic low cl levels. Also, high ph is a chronic problem. Am I doomed to weekly or daily acid addition ?

[PoolDoc]

You're not doomed, unless we fail in our attempts to keep you from following pool store advice!

Regarding what you need to do, and what has to be corrected, the easy way to answer that is to get you started doing what you need to do, and than watch what happens as you do it.

#1 - Add 2 gallons of plain 6% bleach per 10,000 gallons of pool water each evening -- including tonight if you can.
#2 - Get a cheap OTO / phenol red test kit and start testing your pool an hour after each PM bleach addition and again in the AM, no later than 2 hours after sunrise.
#3 - if your pH is below 7.0, raise it. If it's above 7.8, lower it. Otherwise, do NOT worry about ANY of your other chemical levels, for now.
#4 - Order a Taylor K2006 or 2006C -- Amazon links below -- and start using it once it arrives. (Do not test CYA yet -- 2006 kit only holds 3 or 4 CYA tests)
#5 - Tell us what's going on.
#6 - Once we've established that you are not losing most of your chlorine OVERNIGHT (losing it during the day is expected), we can move on to the next step.

Ben