Foz Down vs: GFO

[dcw1sfu]

I keep switching back an forth but i think I'm going to stick with Foz down. As I dose vinegar it keeps my phosphates under control and every time I add even the smallest amount of GFO it completely wipes out all phosphate in my tank (0 on a hanna) and I notice pale corals. I like that with a small amount of Fozdown I can control how much I want to lower my phosphates by.