I have dead algae too..and high CYA

[Nicodemus]

Having the same issue with dead algae… seems to return each day, even after vacuuming. Used the test kit, and as best can tell my FC is 11 ppm, CC is .5, but my CYA test seems way too high… 100+ ?! Added the drops, cloud obscures the black dot, but the level is not even under up to 100?
Must be missing something?

 

[JohnT]

With such extreme CYA you have a low active chlorine level, even at 11ppm FC, so a barely controlled algae problem is a real possibility.

The only reasonable way to get your CYA under control is to replace a lot of water. You can get an idea of your actual CYA level by diluting a pool water sample 50-50 with tap water and doing the CYA test on the mixture. Double the result. This will give you an indication of how much water needs to be replaced.

If you are using pucks or powdered shock, you need to find a different chlorine source. Liquid chlorine or aN SWCG are the best options to avoid excessive CYA.