Black algae on refugium sand

[LMDAVE]

my refugium has had a few different algae’s in it since starting this tank a few months ago, had what appeared to be Dino’s when tank parameters were ultra low, but I was able to manually remove it and it went away. I went through a cycle of chemiclean a few weeks ago since I saw some red cyano spread in DT that was on some coral rocks that I transferred over. Everything has been clean, but now seeing these black patches in refugium. Only change I made recently was increasing refugium light from 12 to 15 hours. My Chaeto doesn’t grow much and my nitrates are starting to rise a little faster than before.

My refugium is pretty bare and plain, 1”-2” of sand, a few palm size rocks and the Chaeto.

Just curious what I should do about these patches I’m seeing.

 

[MombasaLionfish]

I would not worry about it your tank is still new and it's going through the ugly stages get some snails or a lawnmower blenny.