I have caught many wild saltwater fish and inverts for my tanks in the past. With the fish I would soak them in a freshwater bath with a little copper to kill parasites using the idea of osmosis and diffusion. That if there is a parasite from a saline concentrate environment put into a environment of no salt the concentrations in the parasite and surrounding environment will try to equilize causing the parasite to pop. With this method I have had not parasite or diseases. Now I am mainly doing freshwater and want to catch wild fish and inverts. Theoretically it should work the same way with a saltwater bath and freshwater parasites. Does anyone know of a good and easy sterilization process for freshwater fish?