New to this forum-I have a gunite pool which was resurfaced in late April. Previous surface was used for 10 years with no problems of algae EVER! I have been fighting algae at the waterline and ABOVE, yes above water, for 5 weeks. It tends to grow on grout, tile and on the skimmer basket wiers. I have tried shocking. Used pool store recommended algaecide (2 bottles at $28 each) I brush, scrub, brush scrub, 2 hours a day. Raised water level up high and it seemed to get rid of it. Lowered water back down to normal level and it came back. Cleaned cartridges. It is a brownish black color. Some is slimey and some is hard. Soaked wiers in bleach, put back and it grows again overnight. Pool store owner is stumped. He has never seen algae that grows above waterline and so far he can't get rid of it. I use chlorine tabs, granular shock, Endure was added to pool in early June because of calcium line on tile. Water testing shows very high chlorine levels which are "bleaching out" test kit. PH was showing low, but chlorine level may be messing with this. Any suggestions?