I had a Snowflake for about five years in a FOWLR and it never messed with any of my fish, but I did keep it well fed with live shrimp from the bait store.
I first started feeding it by hand because the thing was blind and would not get any food if I didn't. I stoped that when he got my finger by accident or at least I think it was by accident, so I started droping abopout a dozen shrimp in the tank every 2 weeks and man did he start to grow. He was a little over 2 feet when I had to sell my tank.