Chemiclean did not kill this.

[DerekC]

Chemiclean did not kill this so it is not cyano? It is black (or dark dark green?) slimy.
I think I have more than one nuisance algae here. They are in my live-rock refugium tank with UFO grow light.
Ugly, I know, but I did not care until now they are choking my chaeto.
One day with Chemiclean has not made a difference. Hopefully couple more days will. I will now run GFO. H2o2 soon?

But what am I dealing with here? Black cyanobacteria? spirulina?

 

[Skynyrd Fish]

I would consider siphoning all the snot off the rocks and out of the sump. You could also take the rocks out and scrub them with a brush in a bucket of tank water. While the rocks are out of the sump you may want to suck up all the detritus in the sump. Put the rocks back in. I have found I get this when I have a build up in my sand or sump of detritus. My tank always looks great after I scrub my rocks.

 

[Oshengems]

Did you look under a microscope? Looks like dinos

 

[DerekC]

I don't have microscope but I might be able to borrow one.
Dinos? I will research more.
Skynyrd Fish, I did try to clean up the tank and all the rocks. They come back in 1 week.

It is a 3-tier tank consisting of three 40 gallon tanks. Top and middle are full of live rocks. Bottom has 1/3 filled of live rocks and a UFO grow light and chaeto I have been growing. Every couple weeks, I throw in a silverside.
No fish no inverts. Tank is kept at 72 degree. Rocks in the top and middle tanks are clean.

Nitrate was about 25ppm (Salifert). I will test phophate and will dose GFO.

 

[Skynyrd Fish]

what live stock do you have? Interesting setup.

 

[DerekC]

No live stock. Just rocks for now doing curing/cycling. Planning to upgrade my 110G to 300G couple months later and will plumb the 300G to this 3-tier tank for refugium, jail cell for bad-behaving fish, more water volume, whatever experiment I want to do.
Now I need to control this cyano, dino, whatever so that it will not be in the 300G later.