What type of algae?

[chromakey]

Hi:

It is JBJ 29 nano aquarium. It is a few years old but I purchased it last year. I am running an Aquamaxx HOB-1 skimmer using GFO & GAC. I recently treated the tank for Cyanobacteria which the few SPS corals didn't like at all. Also my zoa's have bleached a bit and some don't open fully yet.

I recently removed a toadstool leather coral that I thought was giving me issues.

Also I have some GSP that are close to a hammer coral.

Do people recommend vacuuming the sand bed when doing water changes? The few times I have done it I get a lot of debris out of it.

Thanks,

Michael

Photo from several months ago: