Woke up this morning and noticed this black area under the surface of the sand and was wondering if anyone knows what happened and what to do. Everything else in the tank is doing great except this small colony of what I think are zoos that didn't open up today. Tank is about 2 months old. Here are my parameters
The only thing that's changed is that I added 2# of LS
last week. (the black area is not in the LS
but in the older aragonite)
Doesn't seem to have grown at all over the course of the day. I've hopefully attached two pics. One to show the size of the area and one closeup of the darkest part.
Any ideas are appreciated.