Purple and Black Velvet like Algae. What is it?


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Folks. Has anyone seen this in their tanks. I had some hair algae, and now it is gone but I have this blanket of bright purple and black algae. It looks very soft and when I pull it off rocks, it is snotty like. Is this cyano bacteria? I know that it is pinky purple, but I have never heard of black. Cure hair algae and now this, what next?
p.s. I'll try and post a pic this weekend.
Cyano can be a variety of colors, including black, green, purple, and red.
If it is cyano, has anyone used any of the chemical cures like Chemiclean or Ultra Redslime remover?
those are really only a temp cure for a problem in your tank. What are your feeding habbits, how long have you had the tank up, how often do you do water changes and do you use ro/di water or tap? All these play a role in cyno outbreaks, a lil more info and we can help you a lil better.
I dont feed my tank, havent for months. I use Ro/Di water for top offs. I do 50 gallons every 2 weeks. I also have two phosban reactors running 24/7 and Chaeto in my sump. I am also running a uv sterilizer 24/7.
Either might be a sponge growth of some sort. I believe the simple test is adhesion. If it sloughs right off with just a brisk blast of water whereas a sponge will have to be pulled or scrubbed off. The "snotty" description leans to Cyano.

Sponges are harmless, if not good. Cyano is ... cyano.