With an aquarium calculator, you can approximate heater size and temperature level targets

https://aquarium-weight-calculatorsefq631.urbanvellum.com/posts/don-t-stop-15-things-about-fish-tank-gallon-calculator-we-re-tired-of-hearing

With an aquarium calculator, you can approximate heating unit size and temperature level targets. Make safer options for tropical, cold-water, or planted tanks.