Enter the total volume of the aquarium (gallons) into the Aquarium Salt Calculator. The calculator will evaluate the Aquarium Salt.
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Aquarium Salt Formula
Salt (tbsp) = Volume (US gal) / R
- Volume — tank water volume in US gallons (liters ÷ 3.78541, UK gallons ÷ 0.832674)
- R — gallons per tablespoon based on treatment level (3, 2, 1, or 0.5)
One US tablespoon of aquarium salt weighs about 14.787 g. The calculator converts the tablespoon result into teaspoons, grams, and ounces for convenience. Dose by actual water volume, not tank rating, since substrate, rock, and decor displace water.
Dose Levels and Concentrations
| Level | Ratio | Approx. ppt | Use Case |
|---|---|---|---|
| Preventative | 1 tbsp / 3 gal | ~1.3 ppt | Tonic, slime coat, mild stress |
| Mild | 1 tbsp / 2 gal | ~2 ppt | Minor wounds, early symptoms |
| Standard | 1 tbsp / 1 gal | ~3.9 ppt | Ich, fungus, max 10 days |
| Strong Dip | 1 tbsp / 0.5 gal | ~7.8 ppt | Short bath only, 5 to 30 min |
Species Tolerance
| Tolerance | Examples | Max Safe Level |
|---|---|---|
| High | Mollies, guppies, goldfish, livebearers | Standard |
| Moderate | Bettas, barbs, danios, cichlids | Mild |
| Low | Tetras, rasboras, loaches | Preventative |
| Avoid | Corydoras, plecos, scaleless fish, live plants, most invertebrates | None |
FAQ
Can I use table salt? No. Use plain aquarium or non-iodized salt with no anti-caking agents. Iodine and additives harm fish.
How do I add it? Dissolve the measured amount in a cup of tank water first, then pour the solution slowly across the tank. Never dump dry salt directly on substrate or fish.
How do I remove the salt? Salt does not evaporate or get filtered out. The only way to lower concentration is water changes with fresh, unsalted water.
Do I add salt when topping off evaporated water? No. Only add salt for water you remove and replace during a water change. Use the Top-Up tab to match the existing concentration.
Example: A 30 gallon tank at standard treatment needs 30 ÷ 1 = 30 tablespoons, or about 1.875 cups (~444 g).
