I have skunk and blood shrimp. I also have a six line wrasse. he does not bother them. however, wrasses are a semi aggressive. that should be considered long term and not as just a solution. I would only start with one if you get one and see how that goes. there are other wrasses that will do well as well as other fish. velvet nudies eat flatworms specifically and only flatworms. you will need to get rid of it after the problem is solved. they are rarer than lettuce nudies. So you may have to look. They are blue and black. I would do a little research on the red planaria before doing anything. Just type it in google and read a couple of articles should do the trick.I know I said do it fast, but you should not jump into any big decisions with your tank.