So after treatment the worms do indeed seem to be gone (crosses fingers). Will treat tank again after 1 month. While I did suffer one oto cat death I'm not really sure if it can be blamed on the levamisole. On the other hand the levamisole seemed to stress the fish out ALOT. While the stuff was in the water fish lost almost all appetite and hanged out at the bottom of the tank. My keyhole got really dark and did not feed at all. Before my BN plecs (even the infested one would come out, but they stayed hidden all the time. However, after a big water change and adding carbon to my filter, the fish perked up a great deal. Still not 100% but at least eating a little. Hopefully they will recover soon.