Rust colored dusting on sand

Rust colored dusting growing on sand and starting a little on rocks. What is it? It started about a week ago a few days after I replaced my actinic bulbs. At first I thought maybe cyano, but now I'm thinking it is something different. I had a cyano outbreak a couple months ago and thought maybe it was coming back, but this is different color and not growing as rapidly. Also, this stuff is only growing on one side of tank.

I had the same stuff in my tank after 4 months from start up and it seemed to go away at night and reappear with lights on, i was told it is algae and not harmful and will settle away, and it did after a few months, but what seemed to make it go away I changed daylight to only few hours a day now its gone and tank looks better

What mojuave is describing sounds more like Dino and not what you are experiencing Kelli.

Kelli - you might still have a cyano, but a different strain of cyano. It can come in many different colors.

Mojuave - Dino's are a very different issue and can be very hard to overcome. I would do some searches on how to deal with it.

Being that it only appears in that location, have you tried siphoning the sand in that area? You may have had a big loss of life (snails) or maybe a bunch of food settled in that area. Might be worth a shot.

I did siphon that area and it seems to slowly be coming back in the same area. Diatoms maybe? I don't think it's dinos either like you described mojuave. My clean up crew definitely needs replenished, but I haven't made it to the LFS that has them 20 for 10 because it's a 45 min drive. Petco is the only thing really close to me and I really don't like to buy there just because I have noticed cyano in their tanks plus I can't see spending 2 something on one crab or snail. I have only been running my day bulbs 3 hours lately because I know they need replaced. I run blue 10 hours and my corals are loving it since those bulbs are new. I also hooked back up my algae scrubber. Not sure if it will help, but worth a try. When I ran it before it was only for like a month so I never really gave it long enough to see if it would have the results it is supposed to. My nitrates still run 10-20 no matter what I have did so far. Considering trying to build a sump/fuge, but still researching that. Whatever this is I'm sure it too will pass, at least I hope.