Reef calculator · reviewed 2026-05-01
Reef tank heater wattage calculator
Plan reef heating inside the 2.5-5 watts per gallon band, then split heat across two heaters on tanks 50g and up.
2.5 <= total watts / display gallons <= 5.0
Heater safety band
190-375 W
Use two heaters around 95 W each, preferably controller-backed.
What this catches
The first-order mismatch: too little capacity, unsafe wattage, weak turnover, missing coverage, or a budget that ignores supplies.
What it cannot catch alone
A single calculator cannot verify every product, livestock choice, chamber fit, vendor listing, or future stocking plan.
Why open the planner
The planner combines this result with equipment categories, budget tier, bioload, and compatibility rules.