Ok great thanks.my gsp started 3 months ago about quarter size, I isolated it on a freestanding rock so that it can't reach any other rocks...picture might be deceiving in size, its about the size of an American dollar wrapped around the top of that rock bottom left corner...
Ive got plants in freshwater tanks that got to trim fortnightly and sounds like will take quite some time to cover my back wall and watched some you tube videos and can easily slice off with razor blade if on flat surface like glass