How to treat Black Algae on steps while draining?


Apr 30, 2009
I'm starting to see some black algae on my steps, I"m also draining about 80% of my pool to lower CH. Is there anything I can do to fight the algae while the steps are dry and the pool is draining?


TFP Expert
LifeTime Supporter
Apr 4, 2009
Pretty sure you can just use a nylon brush and diluted bleach to kill it off, but I'll let the more experienced folks chime in.


TFP Expert
LifeTime Supporter
Mar 29, 2007
Coastalish 'down easter'
Why dilute the bleach?? :? Pour that stuff on full strength, scrub a little and repeat! Black algae is a nasty b*stard and you need to have a 'take no prisoners' approach to even put a dent in it.

The straight bleach (the more concentrated, the better) poured directly on it will be quicker than bringing up the cl level in the entire pool. You're doing a great thing by draining the pool to be able to address the B/A - I realize that it's incidental to your having a CH problem, but this is working out in your favor.

Also, a metal brush would do you better with a plaster pool - really 'knock the heads' off the clusters! :cool: