Purple Agae -What is it ?
 

So I seem to be having a bout of this deep purple algae on the glass of my tank (sides and back panes only). When I scrape it off, it comes off in sheets (and the sheets float around and stay intact).

My Alk and Mg are slightly off (3 meq/l and 1075) but other params are where they should be. BUlbs are coming up on a year next month so that could be part of it...

umm im not expert but it sounds like coraline algae to me and thats a good thing! (Its a bitch when its on the glass) If you want you can leave it on the glass the back side if you want... thats what im planning on doing when mine takes off

I have a small patch of the same, I was at a LFS and I spoted some of the same in the dispaly tank. They said it was Cyano. Mine is pretty slow growing.

a pic would be good, doesn't sound like coraline, as it doesn't come off in sheets and float around so sounds like a nusance algae. use a net and remove it when you clean it off.

Steve

Go
 

is it "solid" or does it look slimy?

cyano...
 

Most likely its cyano, as I also have the same stuff.. My sand bed got totally covered and I had to scoop it up and remove it. Its really slimy and stays in sheets.

Coraline chips off, and is brittle. Cyano is like sheet of skin, ugh!

Yeah, this is like velvet -or skin !- when it comes off. it's not on the sand or the rocks, just the glass and it's fairly recent. I do weekly water changes so I'm a little surprised to see this.....

Cause of this is.... ?

Let me guess "excess nutrients" ?

increase water flow to areas where you notice the algae. and continue regular water changes and manual removal.

I also get a purple film (not really sheets and not all that noticeable until the Easy-blade comes out) but don't think it's Cyano by how the Tangs eat it up. Seems they just love it by how they'll follow around the scraper.