I've been thinking about this recently. Just looking for discussion.
What about flatworms?
I got some flatworms recently with some macro algae and now have them in one of my new project tanks. Should I treat the tank? Should I not worry? Wait until they are a plague before making a move?
It's an interesting topic for me. In my home display aquarium I've never had flatworms. The thought of having them in my display is silly. My tank has 9 wrasse in it. There seems to be no possibility of flatworms in there, and I haven't really thought about them in years until now.
Adam