Colleen, happy to help with a good ID.. seems these two get mixed up a bit, silly common names being so similar.
I was about to come worship you in Fort Peirce if you were growing turtle grass so well it was becoming a nuisance! I thought perhaps we could all learn a few things from ya.
I was under the impression that turtle weed is on the tastier side of macroalgae for herbivorous fishes. Is this stuff in your 29 or the bigger tanks? Perhaps the loan of a small yellar tang or a foxface for a week or so would help to really pull it out. Maybe I have my wires crossed again though..
Perhaps Peircho or Triterium will chime in, they're good with the larger fishes.
Otherwise, I think the best alternate is to pull it out by the handfuls as you can from the rockwork. I dont think you'll need to cook the rock or anything that desperate though. You might try giving it away here on RC too.. you never know who'll want things like this.
Good luck!
>Sarah