I've fixed that algae problem. the exact same one. Its a silicate based algae and I got it when I removed all my sand to make my tank into a bare bottom tank. I was using regular filtered oceon water from california. The water, has high phosphates and silicates. Well when I took out my sand I guess it released all those things into the water. and it spiked my tank like a couple days later. I fixed it by doing water 15% water changes with H2O saltwater and AquaMaxx UltraMaxx AIO All-In-One Filter Media<--- this stuff is awesome. Hope this post helps good luck with that. It will take one week. BTW if you siphon it out it will reduce the damage the algae will do. IT WILL KILL ZOAS. IT WILL KILL montis. first hand experience.