Methylene Blue Solution

1. Methylene blue is the best to stop fungus growth
2. Mix 4 grams of Methylene blue in 1 liter of distill water
3. Add in the solution drop by drop until the water in fish tank is blue. It will be safe. The fish can tolerate even as blue as you could hardly see the fish

Salt Solution / Bath

1. For 75 gallons of water, you can add in 3 to 4 tablespoons of salt. Provided it is a bare-tank, otherwise the plants will die.
2. Salt is only to disinfest bacteria and some kinds of parasites.
3. Plants will die if you add in salt.