I've looked at several pics on the net, and the closest thing I've found is caulerpa. It looks very much like the grape species, but instead of having little grapes, it has little lilly pads. Do I need to be concerned about this stuff? Nothing has been added to my tank since July, and this stuff just started growing about three weeks ago. It has been growing like crazy (about an inch per day) since I first noticed it. Will it take over my tank? Do I need to prune it? What will eat it? Or should I just leave it alone? My tank has been running for about 14 months now, and I only have 4 small fish (1 clown 2", 2 firefishs 1.75", and 1 watchman gobie 2.25"). I know people buy this stuff (if it is caulerpa?) to put in their sumps, but is it OK in the main tank? (I have no sump)