🐠 Aquarium
Aquarium Heater Wattage Calculator
Size a heater from tank gallons and how far your room sits below target water temp.
Fill in a few details and watch the numbers wag into place.
Friendly reminder: ask your vet. These tools are smart guesses, not medical advice. When in doubt, call the professionals who know your pet best.
Frequently asked questions
- How is heater wattage chosen for my tank?
- Gallons and the temperature rise you need from room temp to target tank temp drive watts. The tool suggests a heater size that can hold steady heat without running nonstop.
- Should I use one heater or two smaller ones?
- Two lower-watt heaters in large tanks give backup if one fails. Enter total gallons once; split wattage evenly if you run dual heaters.
- What if my room gets very cold at night?
- Cold rooms need more watts or a heater with a reliable thermostat. Never oversize without a good controller, and use a separate thermometer to verify.
- Can wrong wattage hurt my fish?
- Undersized heaters struggle and swing temperature. Oversized units can spike heat if they fail on. Stable temp matters for fish health; consult an aquarium pro for delicate species.