Whats the best way to disinfect a tank?

[Iratus ranunculus]

A 10% bleach solution will do it as well.

It works, but it can also leave a chemical residue. I tend to keep all my feeders in a methylene blue solution. It works very well. Kills any fungus, bacteria, or parasite on or in the fish and is non-toxic to the amphibians. It is safe enough for use with fish eggs...

[John]

Kills any fungus, bacteria, or parasite on or in the fish

Methylene blue is effective against external bacteria and fungi but as an anti-parasitic it has very limited value.