A friend of mine is fighting this thick green algae is his reef tank. Tank had been up and running for 6 months parameters all in check and with the last hurricane here in Florida the tank got hot for 4 days and was shut down. Since then this thick spongy green algae has started. I helped him remove a whole bunch tonight and did a 70% water change. We siphoned bunch of green hair type algae out but this stuff is like stuck on the rocks and almost has a sponge consistency. Any idea what it is??