Coral Heater Wattage Calculator

What is the Coral Heater Wattage Calculator?

The Coral Heater Wattage Calculator calculates the heater wattage needed to warm coral tanks to target temperature. Getting the environment wrong is one of the fastest ways for an otherwise well-cared-for animal to get sick, many species are far less tolerant of temperature or humidity swings than they appear.

Corals generally live 10-50 years when they are well looked after. They are a filter feeder, so their nutritional needs shift with age, size and activity. Corals are colonial animals, not plants, and depend on stable salinity, alkalinity, calcium and strong lighting. They are the least forgiving part of a reef tank, where stability matters more than any single value. Keep an eye out for bleaching from heat or light stress, tissue recession from unstable alkalinity, brown jelly infection. These are the conditions corals are most commonly seen for.

How does the Coral Heater Wattage Calculator work?

The safe range is drawn from husbandry references for corals, since the right environment varies significantly between species. It is a starting point, not a verdict. Somebody who has actually examined your coral will always know more than a formula does.

Factors that matter

• Time of day and season: since ambient conditions can swing more than expected
• Equipment accuracy: a cheap thermometer or hygrometer can be off by several degrees or percentage points
• Placement of the sensor relative to heat sources, drafts, or water
• The specific microclimate needs of the individual species, which can vary even within a similar-looking enclosure

How do you use the Coral Heater Wattage Calculator?

1. Enter the tank volume in whichever unit you use (US gal, L, UK gal)
2. Enter the coolest room temperature in whichever unit you use (F, C)
3. Enter the target water temperature in whichever unit you use (F, C)
4. Press Calculate, then read the result alongside the sources listed below

Worth doing: jot down the date and the result each time. A single number tells you little, but a trend across a few months tells you a lot about your coral.

For related questions, see the other environment tools or browse every coral tool.

Before you rely on this

Two corals with identical numbers on paper can still need different care. Breed or line, body condition, activity level and any existing health conditions all pull the real answer away from the average. If your coral has a diagnosed condition, is pregnant, or is very young or very old, treat the figure here as the loosest of guides and let your vet set the actual target.