Yeah for sure. It wont kill anything, believe it or not. I use a ton on colonies and it works. The twist method works very well with colonies and even small frags. Don't expect to glue something on a point because most often the glue will just squish out the sides and becomes a pain. Set it on the surface with the glue on it...... Hold it there very steady........ Pull it away so there are strings of glue between the rock and frag, quick twist, and squash it back down. Then twist it till it feels level and secure. It doesn't work 100% of the time, but after getting used to it it works well. Gorgos are truly a pain to glue because of the flow in the tank!!!