If you've kept fish, no doubt you've also dealt with sick fish. If you have a fishroom full of healthy fish, you need to be careful when bringing in fish from the outside, from pet shops, swap meets and auctions. While quarantining is essential, you also need to be mindful that you don't inadvertently transfer disease from tank to tank when netting fish or changing water.
A few years ago, I visited my good friend Chuck Rambo in San Jose, CA. Chuck took me a large wholesaler in the Bay Area. We first checked out a cart which included a net and a small container of Net Soak. Before using the net in a new tank, you had to dip the net in the Net Soak and shake it out.
Net Soak is usually a solution of Potassium permangenate which is an oxidizer. It helps to prevent the transfer of disease organisms by oxidation. Unlike other oxidizers such as bleach, it is gentle on nets and your hands, and pretty safe to use. Net Soak prevents most bacteria from spreading, but not viruses.