Problem purple stuff

[AFEICA]

I have a fine purple/ almost black mat growing in my fuge. It covers the sand, the Macros and grows on the walls of my fuge. I can pick it up off the sand, rub it off the walls easily with my fingers, and "flick" the macros with my finger and it all comes off, but it seems to want to "smother" everything. Any ideas what this stuff is or how to get rid of it. It does not show up anywhere else in the the system. (2 tanks and 2 refugiums)

Thanks in advance,

 

[billsreef]

Check your nitrate and phosphate levels. If one is elevated and the other undectable, your macro's could be nutrient starved. This would allow a build up of one nutrient that this particular plague is using. The cure would be to dose the system carefully with the lacking nutrient to pick up the growth of the macro's to outcompete the plague algae This of course requires carefull testing and measured doses in order to find the right balance.

 

[Beenalongtime79]

Cyanobacteria

Cyanobacteria

It also sounds somewhat like a cyanobacteria bloom (should be slimy looking as well) and is only natural... how old is your fuge? Increasing the flow in the fuge will most likely help in the situation.