GSP growth is approximately 10-15% every two to three months, depending on conditions... meaning if you have just a little piece, 10% isn't much. Once you have a significant amount, 10% growth becomes a LOT. It's pretty coral, but you need to be careful where you put this stuff... it will over-run your tank if given the chance, including some other corals. There are many a reefer who regret ever putting it in their tank.
, the best thing to do is put it on it's own rock isolated on the sand bed.... that way it's easily removable for trimming without getting it everywhere
. You can see where I put mine on the bottom-right. I've had that chunk less than a month, and it's already spreading to the rock I placed it on.... What I'll probably do is use that chunk to seed my rock, and then take it to another lfs
or a local frag swap to trade for something else.