Selecting Aquarium Heaters

Selecting Aquarium Heaters

A Gulf Coast Turtle and Tortoise Society Care Sheet
by Marlaina Barr and Bob Smither - GCTTS Members

Turtles should not be housed in aquariums or containers of similar nature under normal circumstances. As responsible turtle keepers, we should always strive to maintain them in as natural an environment as possible. Turtles will not thrive in an aquarium, they need to be outdoors.

There are circumstances where it may be necessary to keep a turtle in an aquarium. These circumstances include over-wintering a sick turtle or one acquired late in the year and over-wintering exotic species that do not hibernate in their natural range. When turtles are kept in an aquarium, an aquarium heater will be required in order to maintain the turtle at a satisfactory temperature. Note that room temperature is too warm for the turtle to hibernate but may be too cold for it to properly digest its food and to maintain its health.

It is important to buy the right heater for your aquarium. There are two basic types - those designed to hang from the side with the top of the heater out of the water and those that can be totally submerged. With either type, it is important that the heater element end of the heater be completely surrounded by water - if not, the heat from the element will likely break the glass. Most turtle setups will not have the water up to the top of the aquarium since there will be basking areas, so the hanging types will not work properly. Even if the heater element is submerged, the thermostat portion (near the top of the glass tube) will not be surrounded by water and will not be able to regulate the water temperature. For turtles, the totally submerged types are recommended. They can be oriented horizontally and therefore completely surrounded by water even in tanks with only a few inches of water.

Note that the use of a glass heater can be dangerous. If the glass breaks, both you and your turtle may be electrocuted. Turtles can be vigorous - be sure to protect the heater from the turtle. A good solution is to bury the heater (it must be the submersible type) in the gravel over an under-gravel filter. The operation of the under-gravel filter will circulate water around the heater. If there is not enough gravel to protect the heater, consider surrounding it with bricks or stones. Some brands have a heater guard that fits around the glass tube and provides some protection.

There are several brands of heaters available. The Ebo Jager heater is considered to be among the best. It is completely submersible, has an adjustable temperature setting knob (although it is difficult to adjust since it is surrounded by the water seal), and uses high quality, shock resistant glass. This last feature is very important - cheap heaters using thin glass tubes will not withstand the onslaught of a vigorous turtle. The Ebo Jager has its temperature setting indicated on the adjustment knob, but you should always check the temperature with a high quality aquarium thermometer, at least until you get the setting correct. Hagen has the Hagen Tronic series that also can be recommended. This series has an electronic temperature control which should be more reliable than the normal bi-metallic strip control mechanism.

When selecting a heater for your setup, do not buy more power than you need. If the heater is too powerful for the size of the aquarium, the heater will cycle more often and will wear out sooner. It is possible, if unlikely, for the heater to fail where it is on continuously. The better heaters have a safety feature that will prevent overheating should the main thermostat fail. You should look for this feature in any heater that you buy.

To make it simple, get an adjustable, fully submersible heater that is the right wattage for the tank. Use a good thermometer to check the water temperature. A good rule of thumb is to use a heater with 4 to 5 Watts per gallon of aquarium size for small tanks and 3 to 4 Watts per gallon for larger tanks. Note that even if the aquarium is not filled, you should select a heater based on the aquarium size since most heat loss is through the top water surface. If you keep your house cool, you should size the heater using the higher wattage number.

Heaters are usually available in 25 Watt steps from 50 to 150 Watts and in 50 Watt steps for large heaters. Using the above rule as a guide you can determine the size of heater for your tank. For example:

Aquarium Size Warm House Cool House
10 gal 50W 50W
15 gal 75W 75W
20 gal 75W 100W
30 gal 100W 150W
40 gal 150W 175W
55 gal 175W 250W
65 gal 200W 250W
75 gal 250W 300W
100 gal 300W 400W

If necessary, you can use two heaters whose wattages total the required power. For example, two 150 Watt heaters can be substituted for a single 300 Watt heater. The two heaters should be adjusted as closely as possible to the same setting. They should be located at opposite ends of the aquarium. The adjustment is correct when both heaters cycle about the same amount.

Turtle setups will normally include a basking area with a lamp. The lamp will provide some heating to the aquarium, but this should not be considered when selecting the heater. The heater should be sized to maintain the desired temperature when the lights are off at night. Note that the turtle must be able to get away from the light source as well to prevent being burned.

Healthy natives should be maintained at about 80F to 82F. If a turtle is sick, it may benefit from higher temperatures such as 88F. When housing exotics, our goal should be to approximate the temperature that the species would experience in their natural environment.

For another page about Aquarium Heaters, click here: What's In YOUR Turtle Tank?

Please contact us if you have questions.
Gulf Coast Turtle and Tortoise Society
1227 Whitestone Lane
Houston, TX 77073
Email us for quickest response:

Copyright (c) 2004 Gulf Coast Turtle and Tortoise Society
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".