In my experience there are some more resistant hydra than others. The photosynthetic hydra (green ones) are easier to kill than the non-photosynthetic(brownish ones). Salt may begin to stress the fish at the levels needed to kill the hydra. Clout is effective, but it's a pretty strong medication. I've found Aquarisol to be very effective, though the brown ones sometimes need a few doses. I haven't had any new hydra in a couple years now--no new plants for me. Zack ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com.