It won’t completely decimate the copepods though, and their populations should be back in a week. Make sure to buy enough Salifert Flatworm Exit to do a 2-4x strength dose though if needed. I suspect that over the years, people didn’t make sure to kill all their flatworms and what was left was a more resistant strain so now we all have to use a higher dose.best way to kill them, read that flatworm exit is good, but will decimate my copepods.
FWE has worked well for me. good luckIf we’re talking about planaria, they don’t lay eggs. Just make sure to add enough FWE to kill them all at once.