🧂 Aquarium Salt Calculator
Enter your tank volume and choose a dose level — general tonic, stress relief, or ich treatment — to see exactly how much freshwater aquarium salt to add, in tablespoons and grams.
🧮 Calculate Your Salt Dose
What is an Aquarium Salt Calculator?
It converts your tank volume into the right amount of freshwater aquarium salt for the job at hand. Choose a general tonic, stress-relief, or ich-treatment strength, and it returns the dose in both level tablespoons and grams so you can measure it however suits you.
Use only true freshwater aquarium salt — never table salt or marine mix — and always dissolve it in tank water before adding it gradually. Many soft-water species, scaleless fish, and plants are salt-sensitive, so research your stock, start low, and follow the product label every time.
❓ Frequently Asked Questions
How much aquarium salt should I add?
It depends on why you're dosing. A general tonic dose is about one tablespoon per 5 gallons, a stress-relief dose about one per 4 gallons, and a stronger ich/parasite treatment about one per 3 gallons. Enter your tank volume and pick a level here to get the exact tablespoons and grams. A level tablespoon of aquarium salt weighs roughly 18 grams.
Is aquarium salt the same as marine salt or table salt?
No. Freshwater aquarium salt is sodium chloride made for tonic and treatment use, without the additives in iodised table salt or the buffering minerals in marine salt mix. Use only true aquarium salt for freshwater tanks — table salt's anti-caking agents can harm fish, and marine mix will alter your water chemistry.
How do I add the salt safely?
Dissolve the measured salt in a cup of tank water first, then add the solution gradually to the aquarium rather than dropping dry salt in, which can burn fish or sit on the substrate. Spread the dose over a few hours for a bigger treatment, and remember salt doesn't evaporate — only add more for the new water you replace during changes.
Are any fish sensitive to aquarium salt?
Yes. Many soft-water species, scaleless fish like corydoras, loaches, and some catfish, and a lot of live plants are salt-sensitive and can be harmed even by tonic doses. Research every species and plant in the tank before dosing, start low, and follow the product label — when in doubt, treat sensitive fish in a separate hospital tank.