Aquarium Water Change Calculator | Safe Water Replacement

1 Aquarium Volume

I know my gross volume Calculate from dimensions

Total Gross Volume

Please enter a valid volume.

Length

Width

Height

Measurement Unit

Please enter valid dimensions (>0).

Estimated Substrate & Decor Displacement Gross volume includes empty space. Net volume accurately reflects actual water after rocks, sand, and equipment.

2 Water Change Goal

Target Change Percentage

Industry standard is 10-25% weekly or 30-50% bi-weekly. Enter a value between 1 and 100.

2 Toxin Reduction Goal

Current Level

ppm

Toxin level currently in the tank. Required field.

Target Safe Level

ppm

Desired safe level you want to reach. Must be lower than current level.

Source Water Level

ppm

Usually 0 (pure tap/RODI water). Must be lower than target.

3 Treatments & Additives (Optional)

Calculate Water Conditioner / Dechlorinator Dose

Enter your conditioner's dosage instructions:

per every

Default is Seachem Prime (5ml per 50 Gal). Dose is calculated for the replaced water volume only.

Calculate Marine Salt Mix (Saltwater Tanks)

Enter your salt brand's mixing instructions:

per every

Default is standard mix (1/2 cup per Gallon to reach ~1.025 SG). Always verify with a refractometer.

Action Plan

Est. Net Volume

Accounts for decor

0
Volume to Replace
Exact percentage target

Conditioner Dose

For replacement water

Marine Salt Needed

Mix before adding