Personally..I would pull it out. I had some in my tank, and now 4 years later I can't get rid of it. *cries* Razor caluerpa leaves VERY long roots. Even when you yank it, if the roots survive, you have more growing then before. This is what I did for a long time, and then it got out of control, and now.. my tank is over run with it. Never again will I have razor caluerpa in my display tank.
Just my two cents, but if you have a sump, I would keep it there. Otherwise you need to be very consistent with your pruning.
