(Sigh) need some help with an ID

[AcroNem]

Luckily I've only seen this small amount so far and it has been removed but just wanting some second opinions of what this is. Thanks in advance.
-J
p.s this is in my 300g flat, so whatever it is, is probably here to stay I just want to know.

 

[Tom Blevins]

Don't know the name of it but stay on it and catch every piece floating because it will wedge and attach to most anything and gets to about 3" long in a couple weeks.

Had it and no tang,foxface,crab or snail likes it.

If it's a plant tank or refugium you are golden but I have a SPS tank and does not work. MAYBE (Bryopsis)

 

[evolved]

That's bryopsis.

 

[AcroNem]

I was hoping it wasn't, it looked a little too thick you be Bryopsis. I removed that little bit it was quite small but it looks like I'll have to find a solution eventually.

 

[Tom Blevins]

Sorry it's a pain once it gets rolling.

 

[AcroNem]

I know I just finished killing it in my DT, but lost a third of my zoas and had bailout on a couple euphyllia polyps. I know they say it's harmless but the tech M treatment really stresses things out. I won't be able to do that in this tank it's in my flat. Too big and too much risk to coral.