Heating & Cooling4 min
Aquarium Heater Size Calculator: Watts for Your Tank and Room
Enter your tank's volume and how warm the room is. The calculator gives a wattage from sera's watts-per-liter guide and the EHEIM heater size rated for that volume.
Category
Heating & Cooling
Aquarium and betta heaters, a heater size calculator, and chillers.
Guides
Heating & Cooling6 min
Best Aquarium Chillers and Cooling Fans for Hot Tanks and Axolotls
Active Aqua's 1/10 HP chiller is the one we would buy for a 20 to 40 gallon tank that runs hot. Here is when a fan is enough, how chillers are sized, and what axolotls need.
Heating & Cooling8 min
Best Aquarium Heaters (2026): Electronic, Titanium and Preset
Fluval's E200 is the heater we would put in a 40 to 55 gallon tank. Here is how it compares with EHEIM's thermocontrol e, a titanium heater with a controller, Inkbird's safety controller and a preset budget pick.
Heating & Cooling7 min
Best Betta Fish Heaters for 2.5 to 10 Gallon Tanks (2026)
Tetra's 50 W HT holds a 5 to 10 gallon betta tank at 78°F with no dial to get wrong. Here are the adjustable, nano and shatterproof alternatives, sized to your tank.
Heating & Cooling5 min
Betta Fish Water Temperature: The Right Range and How to Hold It
Keep a betta between 76 and 81°F, ideally around 78. Here is where that number comes from, why small tanks swing, and how to hold the range in winter and summer.