purple...black substrate

[medican]

What the heck are those black almost purple blotchs on my substrate ????
It looks like mold. Is it good bad or what.........

 

[possum]

sounds like cyanobacteria aka red slime algae. It is not good. But i really am not sure if it is bad either just ugly lol

some of the things i have heard to get rid of it are increased water flow over it and using RO water for topoffs and water changes.

 

[medican]

just got a R/O + DI filter hope to put it to work soon
Thanks