Its not BGA, its just normal algae like you get on hardscape and glass. Doesn't grow on my aqauasoil, just on the sand. I've got no algae anywhere else (Ottos, snail and Shrimp are doing a good job) and its driving me nuts. How do people keep it clean - do I need some bottom dwelling fish to turn it over for me? Vaccing it weekly gets it looking good initially but it grows so fast I have green tinted sand long before the next maintenance.