How much Methylene Blue and salt do I add to a 75 gallon tank for new fish?
1. Make Methylene Blue solution:4 grams of Methylene blue in 1 liter of distill water
2. Add in the solution drop by drop until the water is blue. Its safe. The fish can tolerate even as blue as you could hardly see the fish
3. For 75 gallons of water, you can add in 3 to 4 tablespoons of salt. Provided its a bare-tank, otherwise the plants will die.