Some Sort Of Algea

[Pistol]

Definitely looks like Ostropsis Ovata, they are mixotroghic and can live for months without light. Your in for a battle but it can be won, many have tried the reboot method only to have them come back.
There are 2 methods, the "clean method" and the "dirty method" , I subscribe to the dirty method.
Did you use an algae killer in your tank like AlgaeX?
Do you have a sand bed?

 

[bart84]

Definitely looks like Ostropsis Ovata, they are mixotroghic and can live for months without light. Your in for a battle but it can be won, many have tried the reboot method only to have them come back.
There are 2 methods, the "clean method" and the "dirty method" , I subscribe to the dirty method.
Did you use an algae killer in your tank like AlgaeX?
Do you have a sand bed?

Thats just great.
I would Try the dirty method. I have never used any algea killer. What triggered this was I did a chemiclean treatment for the cyano in my fuge. ( I think it did ). No I have a medium aragonite substrate.
My delema is with the tank in decimation I am tempted to restart it because my wife wants to paint the room anyways and I am sick of my rock work.
If I was to start over how would I get it all off of my rock?

 

[Pistol]

The cyano was probably the last thing keeping it in check, if you reboot I would discard the substrate, remove all the livestock and nuke the system with bleach and restart bare bottom. You would need temporary housing for the livestock while you re cycle the tank and rebuild the ecosystem, some rock from a healthy system would help.