How to use it
Enter the tank's length, width and height (inside measurements), and how full you keep it. You'll see litres, US gallons, water weight and common water-change volumes.
Stocking rule of thumb
The old '1 inch of fish per gallon' rule is only a starting point. Species size, bioload and filtration matter far more.
Frequently asked questions
Why is my real volume lower than the calculation?
Substrate, rocks and décor displace water, typically 10–20%. Use the 'Filled to' box to account for that.
How much does a full tank weigh?
Water alone is 1 kg per litre, so a 200 L tank holds 200 kg before glass, stand and décor. Make sure your floor and stand can carry it.
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