Salt for your Frshwater Aquarium

Another salt related claim is the prevention of nitrite poisoning, which is also a theoretical true statement. This is one common problem we hobbyist encounter. We need a safety and clean water for our fish.

Let's assume your tank is brand new and cycling, or the beneficial bacteria are adjusting to a change in tank inhabitants, or worst case, you killed some bacteria colonies using antibiotics to nuke the small algae glancing at you. But you can't kill all of them by using salt you can slowly kill the bacteria.

Salt can be used to prevent nitrite poisoning, if the chloride ions are 30 times the concentration of nitrite ions. Salt is very helpful and have a big advantage for your fish.

Nitrite reaches a toxic level at about 0.1 ppm, which would require about 3 ppm of chloride ions. Depending on the salt (sodium chloride) used, it might translate to about 5 ppm (given that common salt has a chloride concentration of 60%) to ease possible nitrite poisoning. This in mind, one teaspoon of salt would be sufficient to provide this effect for a 300 Gallon tank.

As a brief summary, 1 teaspoon per 300 Gallons will do as described above. Table salt does contain iodine and anti caking additives (to prevent the salt from clumping together). Iodine is essential for certain plants and animals, and definitely of no concern, considering the low amount of salt and the low concentration of iodine added to the salt. Iodine at this concentration should be rather beneficial instead.