Hi, I have the same problem.......and I have a 17 x33 pool . I was told that it was 70, 000 gallons or litres! I cant remember. I was told to turn my pump off overnight by a pool store and let the algae settle and then vacumn to waste in the morning or evening. If you vacumn like you normally do, you dont get rid of the algae it goes into the filter?? Dont take my word, as I have a post on here and am waiting a reply also.
My chlorine level is very high in the pool. and I am not sure if this in itself will get rid of the algae without vacumning it up.