Help!! Algae ID

I've had my 90g up and running for a few months now and I've been fighting some sort of algae that I can't seem to beat... or identify. Before setting up my 90 I had a dino outbreak in a 45g that I successfully got rid of by dosing hydrogen peroxide so I tried that again thinking I had dinos but to no avail. I did about a month long stint of the peroxide daily and also tried Vibrant after reading some reviews online.

The algae is almost like a sheet of bubbles, is clear for the most part, and is located only on the rock and not the sand bed. I tried not dosing the peroxide for about 10 days, and didn't do much else beside clean the glass once, hoping to see more of the string like algae I saw previously but there was no change to the overall appearance.

I've got a ball of chaeto in my sump that's a little bigger than a softball when I compress it together and seems to be doing really well. I've taken an airline tube and siphoned off everything I could a few times while I was dosing peroxide but it just came back. I haven't tried a complete blackout yet, though I did reduce my light period by a few hours. Not currently running GFO as I'm worried it would just be expended in a couple of days. All water is from a brand new BRS 4 stage and the inline TDI meter is showing 0. All parameters are normal including Mg.

All corals, all 6 frags is all, are doing really well and don't seem to be bothered by the algae but I'm hesitant to add anymore until I figure out what's going on. Anyone know what I'm dealing with or have some suggestions? Thanks!

 

The rock is BRS Reef Saver that I had in a plastic tub with a powerhead for at least 2 weeks. While it was in there I was dosing lanthium chloride to remove phosphates. Once it tested 0 I rinsed it well and put it in the tank. Maybe I didn't do as good of a job as I thought with the LC.

 

Clean up crew consists of some crabs and nassarius but nothing seems to be touching them. Took the pics into the LFS and they're thinking a strain of dinos still. Guess I'll just keep doing what I'm doing and hope for the best.

 

Personally I like to read success stories when it comes to people beating algae in their tanks so I'm happy to report I've been able to beat, or got lucky with, whatever this stuff was. The things that seemed to work for me were: dosing Vibrant, siphoning off as much as I could pretty much daily with an airline tube, and watching how much I feed. Could have been possible there were still some phosphates leaching out of the rock I suppose and it finally was done too. In any case, back to adding livestock!