My water is green!

[monkeyratman]

I can't get rid of a green dust (dead algae) that is floating in and settling on the steps of my pool. There is nothing on the sides of the pool as I have shocked it and brushed what algae there was off the sides . These are my chemicals:

pH 7.5
Cl 9.0
CYA 55
Temp 87F

22,000 gal in ground
sand filter
new pump motor
skimmer socks
1/2 cup DE

I did switch to the Cl pucks because the bleech got my CYA down from over 100 over the last year and it is just easier to fill the feeder every 2-3 weeks than going to Wally World every Saturday (I know, that makes me a heretic)Thanks for your help.

Steve

[JohnT]

If it's green, it's not dead. That's probably why it isn't going away. Algae turns a gray-blue color when it's dead

[aylad]

You need to get your chlorine up to 20 ppm and keep it there until you're no longer losing chlorine from sundown until sunrise the next morning. This will mean testing 2-3 times a day and adding whatever amount of chlorine you need to bring it back up to the 20. The key to killing the algae is sustained chlorine levels--just shocking once won't do it. You'll see the algae turn white/gray like JohnT mentioned, and your water will become somewhat cloudy. Keep the filter running 24/7 until it clears, and the green will stay gone (provided you keep your chlorine high enough afterward).

Janet