Aquarium Heaters & Thermometers

What size fish tank heater should I choose?

Knowing what type of heater to buy for your aquarium is only part of the picture.  What aquarium heater size do I need? Picking the right heater for your tank may be a little tricky, so at Kellyville Pets, we have organised to have this aquarium heaters guide to help choose the correct watts per litre for your aquarium and correct temperature requirements!

The other way to select a heater is using the formula 1 Watt = 1 Litre. So once you know the size of your aquarium, it's easy to figure out the heater size.

Mini Aquarium Heaters

Some fish such as Bettas (or fighting fish) are kept in small tanks or bowls. Mini tanks and fish bowls can be quite a challenge to heat properly due to the size of the tank so for these there are mini heaters available that sit outside and under the tank.

Fish Aquarium Heater Placement

You have a heater, but now you are wondering where to put it. Should it be placed in the middle or on the side? Is a front or back placement preferable? Does it even matter? There are some simple, but important, guidelines for proper heater placement. We have aquarium heater suction cups to ensure proper placement. 

The best location to place an aquarium heater is near the water flow, such as the outlet (or inlet) from the filter, or in the stream of a power head. Why? Because having water flowing directly past the heater more quickly and evenly disperses heated water throughout the tank.
If you have a tank that is over 40 gallons, consider having two heaters placed at opposite ends of the tank. The water temperature will be more uniform throughout the tank, and in the event one heater fails the tank will not be completely without heat.

Aquarium Heater Problems

Even under perfect conditions, problems can arise. One of the most common concerns is Aquarium heater breakage. If that is a concern for you, perhaps you should consider using a aquarium heater guard. Another heating challenge is during the summer when aquarium water temperature rises too high. Sometimes turning off the heater isn't enough to avoid dangerously high water temperatures, and additional steps are needed to keep your fish cool like using aquarium chillers. In the winter, the opposite problem can occur. This is especially true if your aquarium heater fails during the cold time of year, and steps must be taken to keep your fish warm.

Our range of Aquarium heaters online include Aqua one Heaters, Eheim Heaters, Aquamanta heaters and a range of Aquarium Thermometers.

Types of Aquarium Thermometers

There are three basic types of fish tank thermometers available: stick on the outside type, float/standing in the water type and digital thermometers. Different types of thermometers are better suited to different styles and sizes of aquariums. Regardless of the type you choose, we recommend using a thermometer for every tank, and record temperatures regularly to ensure the aquarium water temperature is stable and in the optimal range for your fish.

Stick On (LCD) Thermometers

Stick on thermometers are the most widely used thermometer in freshwater aquariums, often provided as part of the new aquarium package. They are usually referred to as LCD (Liquid Crystal Display) thermometers. LCD thermometers are accurate enough for general use, versatile, easy to use, and inexpensive.

Floating or Standing Thermometers

Floating or standing thermometers are placed inside the aquarium, giving a more direct measurement of the water temperature. There are several styles, including ones that stick to the inside of the tank with a suction cup, ones that hang on the inside with a clip or  ones that float around in the water.  Like LCDs these can be placed wherever needed and in the case of large tanks, multiple thermometers may be used at either end of the tank. The standing models sink, which allows for a temperature reading near the bottom of the tank.

Digital Thermometers

Digital thermometers consist of a probe that is placed in the tank which in turn connects to a digital display outside the tank. Some connect wirelessly, while others have a cord that physically attaches the probe to the display. Generally these models require batteries to operate, although some models plug into the wall. Some models provide an audible alert feature that will sound an alarm when the temperature falls below or above the desired range. Although these models are usually fixed in one spot, you can easily move them to take a reading in a problem area of the tank.