Never seen this before? ID please?

[Reefin' Alaska]

I’ve never seen this before and can’t find any pictures like it. It looks like it’s growing in sheets or something.

Any idea?

 

[Isopod80]

Sea lettuce (Ulva sp.)

 

[Reefin' Alaska]

Sea lettuce (Ulva sp.)

Anything I can really do about it? Remove from rock?

 

[Isopod80]

Yeah, you can pull it off and scrub the rock. Some fish like tangs love the stuff. It can be invasive and spreads quickly. Some people use it in their refugium instead of chaeto. It's very good for nutrient uptake.