I have this GSP rock. I had it in my 20 gallon for almost 2 years and never showed a sign of the stuff. Then I put it in my 10 gallon and al of a sudden, feather caulerpa everywhere. Weird. This weekend I was gonna pull the rock and rip as much as I could off. Didn't know if anyone wants it. Only bad thing, the tank does have red flatworms. So, just lettin' you know if you did want it...
Steve


Steve