I have this bubble algae growing in a few places in my tank and in some places it is very heavy. I am not worried about it and kind of like it, but anyway, I noticed that it is just growing on my home made cement rock or the cement on bottles and none of it is growing on any real rock. It started in my algae trough which is a screen coated in cement. The trough was so filled with this bubble algae that it overflowed and the entire thing fell into the tank from the weight. I find this extreamly facinating that "rocks" made with cement that have been in the tank for many years, some decades could still leach something into the water to attract or at least allow these forms of algaes to live. My cement algae trough was so covered in this bubble algae that I removed the screen and threw it away and replaced it with a clean screen with no cement on it but I think that was a mistake. I am going to replace that screen with a cement coated screen for two reasons. I don't want my reef covered in this bubble algae (although I like it in some places) but it "may" be beneficial for the water. I love this stuff.