Help, need a plan to deal with unknown algae issue.

[GentlePuffer]

Here I am dealing with a green coating on my sandbed and scape. I thought it was dinos, but I think I'm wrong. Any idea what I'm dealing with here guys? When I blow at it with a baster on the rocks, it comes right off. Any input in much appreciated at this point. Thanks

 

[Rmckoy]

A list of current parameters , as well as lights , lighting schedule , tank inhabitants , feeding routine ?

 

[GentlePuffer]

Nitrate .05
Phos: .01
Calcium untested
Mag untested

20 gallon red sea 2yrs running, ai prime with a diffuser running at 10-20% for the past month dealing with this issue. 10% whites, 50% uv and blues for 6hrs ramp up, ramp down every day. Nero 3 for flow. The tank was extremely stable until a few months ago. I've tried one month of bacter7 & peroxide dosing, then a month of water changes 2x a week. A 72 hr blackout. Nothing seems to help. I'm debating on going with a chemiclean treatment next but I would appreciate some input first before I do so.

 

[GentlePuffer]

Nothing but softies & a few lps in this tank. I made it for my grandmother and it's in her home. Tried to go super simple and it was going smoothly but I must of got a bloom of some sort. Inhabitants include clown, royal gamma, 3 damsels, 1 cardinal, & standard cuc.