Doc, Help Erradicate This Crap!

[TJcop]

Please help me!
This tough, brown plant has been growing like mad in my tank since it cycled. I pull handfulls of this crap off my rocks and it never seems to quit. I think someone ID'd it for me at one point and said (unfortunately) that it's an indicator of good water quality. Double edge sword, hey?
Anyways, could you ID it again for me and give me any, any, any advice on getting rid of it? It's smothering my poor corals and it's not very attractive. Attached is a pic. Thank you!!!!
http://www.tjstheater.com/crap.jpg

[rshimek]

Hi T. J.

It looks like a species of Dictyota. This stuff is difficult to eradicate, as you have discovered. Probably the best biological controls will be long spined urchins, Diadema species. I really can't think of anything else that might eat it. Other than that, about all I can suggest is manual removal.

Sorry not to be of more help.

[TJcop]

Thanks for the reply Doc.
Will the long spine urchins (I assume they're the black spined ones) harm my SPS corals. I had a short spine urchin once in another tank, and it seemed to just eat stuff off the rock like coralline. I suppose a tuxedo urchin wouldn't work? Thanks!

[rshimek]

Hi T. J.,

Most urchins will eat corallines at one time or another. On natural reefs the macroalgae are primarily controlled by Diadema grazing. I think Diadema is the only hope you have, frankly.