i bought some green stars at lfs and in a few hours i was looking at them closer and saw they had flat worms all over it. i said ''0 NO YOU DON'T, I'LL TAKE CARE OF YOU RIGHT NOW'' i got a bowl of R/0 water, took the stars out of the tank and diped it for 10 to 15 sec. the flat worms died instantly. the stars stayed in for 2 days. now they look great!