Sawtooth Caulerpa

[Soupysteve]

I've been out of the saltwater end of aquarium-keeping for over a year now. I did influence one of my friends enough that he started a 20 gallon long tank. His tank is beautiful - except for an infestation of "sawtooth caulerpa". What eats this stuff that he could keep in his small tank? The only solution I had for him was to upgrade to a 55 gallon tank - then introduce a Foxface or a juvenile Tang.
I figured I'd ask this online community for him - as I 'd hate to see him tear down his tank in frustration when he has some truly incredible SPS growth going on in his tank.
Thanks in advance!

 

[Reefscape]

Tangs are about the most common feeder on caulerpa...There is a lot of debate on seaslug forum about using one of them, but the concensus i get is that its not desirable or effective to use one...Even with tangs, your not guaranteed its going to graze on it sufficiently enough...