Red Algae???

[Ichthus]

What is this? I have been getting this on the sand against the glass lately. I also seem to be having an outbreak of bubble algae. I have 3 emerald crabs and am thinking about getting more as they seem to be popping up all over.

But mostly I was wondering if the red stuff growing is good or bad and what I should do about it.

[dark horge]

It looks like it's just cyanobacteria.
No biggie.

A lot of folks find it unsightly and conceal the sandbed's profile behind panelling. Biologically, there's no problem to it. "In" the sand, it's out of reach of many herbivorous and other environmental pressures, and yet it unnaturally has access to light via the aquarium glass.


hth.