Tank Setup & Sizing
Work out volume, stocking level, equipment and substrate before you buy anything. For per-species gallon recommendations, see the species tank size calculators.
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Aquarium Size Calculator
Enter inside dimensions to get volume in US gallons, UK gallons and litres.
Calculate volume →
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Fish Tank Stocking Calculator
Add your fish and tank size to see the stocking level, bioload and minimum tank checks.
Check stocking →
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Aquarium Equipment Calculator
Heater wattage, filter flow, air pump size and lighting for a freshwater or saltwater tank.
Size equipment →
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Aquarium Substrate Calculator
How much gravel, sand or soil you need for your tank footprint and target depth.
Estimate substrate →
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Aquarium Planner
A setup checklist, stocking guide and cycling timeline for freshwater, saltwater or shrimp tanks.
Plan a tank →
Water Quality
Turn test-kit readings into a clear verdict on what is safe and what needs fixing.
Fish Compatibility & Feeding
Check tank mates before you buy and feed the right amount once they are home. For detailed pair-by-pair answers, browse the fish compatibility guides.
Koi Pond Calculators
Size, stock, filter and treat an outdoor koi pond.
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Koi Pond Calculator
Pond volume in gallons and litres, plus koi capacity, pump flow and liner size.
Calculate pond →
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Koi Pond Stocking Calculator
How many koi your pond can hold for its volume, fish size and filtration.
Check koi stocking →
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Koi Pond Pump Calculator
The GPH your pond needs at its real head height, including pipe friction and waterfall flow.
Size a pump →
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Koi Pond Liner Calculator
Liner sheet size, nearest standard size and underlay for EPDM, PVC or RPE liners.
Size a liner →
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Koi Pond Salt Calculator
How much pond salt to add to reach a target concentration, split into safe doses.
Calculate salt →
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Koi Feeding Calculator
Daily food weight, feedings per day and food type by koi count, size and water temperature.
Plan koi feeding →