How much salt is too much for aquarium plants?

Aquarium plants generally do not well with salt (or sodium chloride), but a concentration of 1 tablespoon of aquarium salt per 5 gallons of water is generally considered to be safe. Also, in our personal testing, 1 teaspoon of marine salt per 20 gallons of RODI (reverse osmosis deionized water) water was beneficial to aquarium plants because of the added minerals.

For more information on how to treat sick fish with aquarium salt, see our full article.