Aquarium Salt Dosage Calculator

How to Use This Tool

Follow these simple steps to calculate the correct aquarium salt dosage for your tank:

1. Enter your tank's total volume in the Tank Volume field. Check your tank's manual or measure length × width × height (in inches) ÷ 231 to get US gallons.
2. Select your tank volume unit from the dropdown (US Gallons or Liters).
3. Choose a dosage strength based on your needs: Mild for routine maintenance, Moderate for common illnesses like ich, Strong for severe infections (use with caution).
4. Click the Calculate Dosage button to see detailed results.
5. Use the Copy Results button to save the dosage to your clipboard for reference.
6. Click Reset to clear all inputs and start over.

Formula and Logic

This calculator uses standard aquarium salt dosage guidelines recommended for freshwater home tanks:

• Tank volume is converted to US gallons first, as most dosage guidelines are based on US gallon measurements.
• Dosage rates are calculated as follows:
  • Mild: 1 teaspoon of salt per 5 US gallons of water
  • Moderate: 1 tablespoon (3 teaspoons) per 5 US gallons of water
  • Strong: 1 tablespoon (3 teaspoons) per 3 US gallons of water
• Results are converted to multiple units (tablespoons, teaspoons, grams, milliliters) for flexibility, using average weights and volumes for granular aquarium salt: 1 teaspoon = ~5.69 grams = ~4.93 milliliters.

Practical Notes

Keep these real-world tips in mind when using aquarium salt:

• Always dissolve salt in a small cup of tank water before adding it to the aquarium to prevent osmotic shock to fish.
• Remove activated carbon from your filter before adding salt, as carbon will absorb the salt and make the treatment ineffective.
• Strong dosages can harm live plants, snails, shrimp, and scaleless fish (like catfish or loaches) — use only as needed for short treatment periods.
• Measure tank volume accurately: if you have substrate, decorations, or equipment in the tank, subtract 10-15% from the total tank volume to get the actual water volume.
• Aquarium salt is pure sodium chloride — do not use table salt with iodine or anti-caking agents, as these can harm fish.

Why This Tool Is Useful

Over- or under-dosing aquarium salt is a common mistake for home hobbyists, leading to ineffective treatment or sick fish. This tool eliminates guesswork by:

• Providing precise measurements in units you likely have on hand (teaspoons, tablespoons) or can measure easily (grams, milliliters).
• Adjusting for tank volume units, so you don't have to convert liters to gallons manually.
• Flagging safety concerns for stronger dosages, helping you avoid accidental harm to tank inhabitants.
• Saving time compared to manual calculations, especially for larger tanks or custom dosage strengths.

Frequently Asked Questions

Can I use table salt instead of aquarium salt?

No, table salt often contains iodine and anti-caking additives that are toxic to fish over time. Always use pure aquarium salt (sodium chloride) with no added ingredients for tank treatments.

How often should I add aquarium salt?

For mild maintenance doses, you can add salt every 2-4 weeks. For treatment doses, replace 25% of the tank water (and add salt to the new water) every 3-5 days until the treatment period ends, to account for salt removed during water changes.

Will aquarium salt kill my live plants?

Mild doses (1 tsp per 5 gal) are usually safe for hardy plants like java fern or anubias. Stronger doses (above 1 tbsp per 5 gal) can damage or kill most live plants, so remove plants before treatment if using a strong dosage.

Additional Guidance

For best results when using this calculator:

• Test your water's salinity with a hydrometer if you are using salt for long-term treatment, to avoid gradual buildup.
• Gradually increase salt dosage over 24-48 hours for sensitive fish, instead of adding the full amount at once.
• Store aquarium salt in a dry, airtight container to prevent clumping, and keep it out of reach of children and pets.
• If you notice fish acting lethargic or gasping at the surface after adding salt, perform a 25% water change immediately to reduce dosage.