We have just returned from 8 months over seas and we have black algae, big time. We have about a 25,000 gal Gunite pool. I have been told the "best" way, although not the easiest way to get rid of it was to drain the pool and to either steel brush or use a pressure washer to knock the "heads" off and then to scrub it with liquid chlorine and\or tri-clor tabs until it turns "pinkish-brownish" - then do it again just to be on the safe side. Was told to add a "super-chlorinate" as we fill it up that will take the FC to about 15 PPM and that should do it. On its surface this process makes sense to me but I am not a pool expert. Honestly, at this stage, if this is "surest" way that is fine with me to get rid of it, this process is OK. This pool is in Texas.
What are your thoughts, comments, additional advice etc?