Red Slime? Cyano?

[Clowny88]

As you can see in the pics, my tank stays very clean... Except for the one trouble spot in the middle where a red slimy algae has slowly developed over several months.

A few months ago, these rocks were transported from another tank, I brushed this rock clean because it had slight traces of algae on it and now it has slowly come back.

I have a low bioload, low nutrient system, no old bulbs, etc. So I'm trying to figure out if this was a problem that's followed the rock or if I've created it in this tank (low flow, etc.).

And then of course, what the best step would be to eradicate and prevent goi g forward... without tossing the rock, which has a very healthy GSP on it which has taken hold for quite a while.

Thanks for the help RC!
http://i731.photobucket.com/albums/ww315/rjeffrey88/Mobile%20Uploads/20150620_102014.jpg
http://i731.photobucket.com/albums/ww315/rjeffrey88/Mobile%20Uploads/20150620_102029.jpg
http://i731.photobucket.com/albums/ww315/rjeffrey88/Mobile%20Uploads/20150620_102041.jpg

[CStrickland]

Have you tried pointing a power head there? It looks like it's growing where there isn't much of a breeze cause your flow is just swirling around the top of the tank.
Also, suck as much as you can with a siphon whenever you get a chance.

[Dkuhlmann]

Pointing powerheads and all the "tricks" don't work on getting rid of cyano. It will run it's course. You can peel it off in one sheet every 4 or 5 days and wait for it to come back to do it again. I've tried everything and what will work is Chemiclean, but I don't want to put it in my tank even though it is said to be reef safe. Mine is finally coming to the end of it's cycle. It will take about 3 months or so to run it's course. Don't sweat it or you will drive yourself nuts over it.

[downbeach]

Sucking it out periodically will help. It does look like its on the "leeward" side of the flow, so redirecting one of the PH's to provide more flow to that area may help.

[Sk8r]

Is there possibly a ray of sunlight that hits that spot any time of day? That can do it.

[Clowny88]

Thanks for all the great feedback and I apologize for the late reply... I wanted to respond back once I'd made some changes.

First, I pulled the rock itself out and scrubbed what I could off with a toothbrush. What was on the sand siphoned out pretty easily... I was surprised.

I moved my powerheads lower and pointed them at the sand... It was definitely my dead spot of the tank. I get lots of oxygenation in my sump so that's not a worry.

There isn't sunlight that hits it during the day... It's in the basement... But I may shorten my light cycle a little.

I'll post updated pics and keep updating the status of this. Thanks again everybody!