Any idea what this is

[jl283467]

This is all over my rocks any idea what it is it brushes off easily but comes back by the next day.

 

[jdpeters]

Looks like a dead spot for detritus to collect.

 

[jl283467]

I thought that too but I have Neptune waves in the tank so there is tons of movement

 

[Eckolancer]

I thought that too but I have Neptune waves in the tank so there is tons of movement

Do you have direct flow on the rock? If not then is it detritus collecting. Also by a lot of flow what are you talking about? Like my tank I have a lot of flow. It's a 108 gallon with 2-6095s and the largest tunze wave box. I run sand less bottom as I like to blow all poop around and catch it in filter socks.

 

[jl283467]

I have 150 gallon with two Neptune waves with all kinds of currents and the stuff is blowing around on the rocks the weird thing is that it seams to grow and it started out of the blue one day I have had the same setup for years with the same fish but the last 6-8 months this has been happening I have a very robust filtration system and do weekly water changes and grow Cheto and other Algeas in my fuge as well as run carbon and gfo