Any idea what this is? cyano or dino?

[joeg123]

Been into reefing just over a year, never had anything like this before, it started off red slime algae and then slowly turned brown, I did a water change and it grew so fast

I tried a 5 day blackout and it was clean when I unwrapped the tank, a few hours later it was back

I've bought a UV stererlizer today in hopes of getting rid of it, I thought it was dino but I've just tested the water and nitrates are 10 and phosphates 0.06

I currently have cheato in the sump but I've left that off during the blackout, should I turn it back on?

 

[MnFish1]

Unfortunately - with a MAC - can't see the video. One way to test is if you use a siphon (not really strong) - can you easily suck it off - is it more like a mat - or strings? Also - I would turn the light on your chaeto back on - or you're going to have more problems - with dead chaeto (assuming thats what you meant about the chaeto in the sump)