Weird black cyano/mat algae

[Shorty Kat’s Reef]

Hi, Iva had my ranking running about 6 months using rock from a previous tank that was over 5 years old.

Acouple days ago this weird black/dark purple algae showed up. It’s like a thick mat on the sand that feels like super thin leather.

Anyone have any idea what it is?

It’s the stuff on the right in the picture but in real life it’s black not purple. The lighter stuff on the left is cyano and is completely different.

 

[Tangdora]

Also cyano, just a dense cluster of it. If you were to stir it (don’t) it would all break apart . I typically turn off power head to prevent it from blowing and just grab the mat of it that formed and remover it.

 

[mmorrison55]

Looks like cyano to me. it should siphon out easily. May have to stay on top,of it for a few weeks, siphoning, adding coral snow mixed with beneficial bacteria, rinse and repeat every few days.

Try and fix your flow in the mean time, and you should see it gone in a month or so.

 

[Mr. Mojo Rising]

Looks like the cyano mat is thickening up, it will appear a darker color when its thick. Although its generally unknown what causes cyano, its thought to be low flow and build up of dissolved organics. Perhaps try to increase the flow in that spot and perform some water changes. Good luck