Aquarium Heater Size: Everything You Need To Know!

Do you want to discover which heater is best for your aquarium’s cold-blooded animals? Cold-blooded species live in the warmth of the water to maintain their body temperature in your aquarium. It essentially means that you’ll have to heat the water your fish dwell in to maintain their body temperature. 

There are several choices to make and a lot of options when it comes to the gravel, filter, plants, and lighting of your aquarium. On the other hand, the fish tank heater is a crucial component that is frequently disregarded. Several types of fish demand different temperatures, so ensure you research the requirements for the species you choose.

Water temperatures of 80 degrees or greater are required for fish, and a water heater is necessary to achieve and sustain these levels. Aquarium heaters, like tanks, come in a variety of sizes, with a variety of features also at a range of pricing points. 

Stability is one of the most significant elements of aquarium water temperature. As a rule of thumb, the water temperature must not fluctuate over a few degrees regularly. It’s essential to have a reliable heater that can keep the water at a steady temperature.

We have assembled a list of water heaters on this blog post, together with heater capacity, or heating power, as represented by its wattage rating, so you can pick one that’s right for your aquarium.

Types of aquarium heaters

There are two types of heaters: internal heaters and exterior heaters. Internal heaters have a heat source in the fish tank, but external heaters do not. Internal heaters involve Hanging Heaters, Submersible Heaters, and Substrate Heaters, while External heaters involve In-Line Aquarium Heaters, In-Sump Aquarium Heaters, and In-Filter Aquarium Heaters.

How do I choose aquarium heaters?

The heaters listed below are aquarium heaters that you can choose from and utilise, depending on the size of your aquarium. 

Internal heaters

Hanging Heaters

The hanging heaters are one of the most affordable and famous among their users. To assist inexperienced aquarists in maintaining the proper water level for tropical freshwater fish, almost all aquariums come with a hanging heater. Such heaters contain a glass tube with a heating coil inside that hangs from the upper portion of the water tank, typically behind the fish tank. Hanging heaters should not be used in marine or brackish water aquariums because salt can invade the tube and create erosion or electrical shots.

Example: NATLIS, and  Finnex 500-Watt Hang-On Electronic Controller Aquarium Heater

Submersible Heaters

Submersible heaters are totally buried in the tank’s water and can be mounted vertically or horizontally on the rear of the tank. They’re frequently placed horizontally toward the ground. Submersible heaters, particularly in more giant tanks, include more constant and effective heating than hang-on heaters. Keeping it horizontally will allow the thermostat to acquire a precise measurement of the tank temperature and accurately turn on and off the heater. Also, remember to leave sufficient space between the water heater and the gravel side to avoid it burning. 

Examples: INKBIRDPLUS 300W, HiTauing Aquarium Heater, and Orlushy Submersible Aquarium Heater

Substrate Heaters

Whether for hobby or pet care, Aquarium substrate heaters are the least frequent internal aquarium heater. The heater’s element is the wire, which warms the gravel in the tanks when the heater is turned on. The gravel then radiates heat into the water, warming it. The thermostat will turn off the heater when the water is sufficiently warm. Substrate heaters are a hugely helpful planting tank because gravel acts as an insulator, protecting plant roots from becoming too chilly. This difficulty is solved by using a substrate heater, which keeps the gravel nice and warm while keeping the plant roots healthy.

Examples: Exo Terra Substrate heater, substrate heater mat

External heaters

In-Line Heaters

External aquarium heaters that are self-contained and installed on or along a portion of an exterior pipe are referred to as in-line aquarium heaters. A water pump is required to circulate water via in-line aquarium heaters. Water is extracted from the water tank, passed through a tube or pipe, and warmed before being delivered to the water tank.

In-Sump Heaters 

This kind of aquarium heater is typically a subsurface aquarium heater positioned in the trickle filter’s water tank, rather than in the aquarium directly. By reducing the hazard of aquarium heaters, this setup offers improved fish security. Highly aggressive fish, like Oscars, reduce the likelihood of crashing or falling into the aquarium heater and breaking it.

In-Filter Heaters

Canister filters are the most popular kind of fish tank filter, although there are also power filters and different sorts of filters having built-in heating elements. Such heaters raise the temperature as it passes over the filter, purifying it and returning it to the tank. In-filter heaters are filters that are located within the filtration and are often integrated with the filter.

Regardless of where they are about your tank, all heaters offer distinct controls. Before operating your heater for the initial time, and especially before introducing fish to your aquarium, you must read the instructions that came along with it. Give sufficient time for your aquarium water to warm up before introducing fish so that the glass and water reach equivalent temperatures and the glass does not crack.

How do I calculate what size aquarium heater I need?

Choosing the right heater for your aquarium is only half of the equation. There are various sizes of heaters available. The capacity of water in the tank, the typical warmth in the area where the tank is placed, as well as the ideal water temperature for the tanks, are all factors in determining the size of a tank heater. The general rule of thumb for heater wattage is to utilize approximately 2.5 and 5 watts per gallon of practical aquarium water capacity. A 100-watt heater should be used in a 20-gallon aquarium. Based on how much you would like to boost the temperature, extra wattage is typically needed. When you’re utilizing multiple heaters, the combined heating ability of all of them should equal the necessary watts.

Are you unsure about the size of the heater you should buy for your aquarium? 

Depending on the surrounding temperature and the capacity of water in the tank, it is possible to calculate the right size heater. Reduce the room’s average temperature from the aquarium water’s desired temperature to account for room temperature. The quantity of heat needed, expressed in degrees, is the outcome.

Where is the best place to put a heater?

To guarantee uniform heating, place your heater beside a filter inlet/outlet or a circulating pump. For maximum performance, submersible aquarium heaters should be put horizontally towards the bottom of the tank. If you want, they can also be aligned vertically. Place artifacts far from the heater so that water may properly flow over it.

If your tank is larger than 40 gallons, use two heaters, one at each end, rather than one 200-watt heater. The temperature of your water will be extra consistent around the tank, and if one of the heaters fails, the tank would not be left entirely cold.

What is the best aquarium heater?

The Fluval E200 aquarium heater is the best, as well as the more effective and secure. It has an excellent built-in heater guard, providing it with a safer and dependable heater. It has a digital display that tells you if it’s in heating mode or standby and will often warn you if the aquarium temperature is dangerously low. This could mean the distinction between avoiding calamity and sacrificing an entire tank of fish.

Tips for using aquarium heaters

• Using hang-on and submersible heaters, it’s recommended to employ multiple units. This ensures uniform circulation of heat and reduces the load on the heaters. It’s generally a good idea to acquire an extra heater just in case.
• Examine the area surrounding the tank for heat inputs and temperature changes. The tank could be near an exhaust pipe or other frequent heat sources, causing the temperature to fluctuate.
• The thermostat control on certain heaters has particular numerical sets so you can tune it to the correct temperature. Other heaters feature dials that range from bottom to top, with no indication of precise temperatures. The previous is simpler to operate but carefully double-check that the heater setting keeps the aquarium at the proper temperature.
• Make sure that your heater is keeping the aquarium water at adequate temperature by operating an aquarium thermometer. To confirm that the water temperature is consistent, move the thermometer about the aquarium and monitor the temperature in different spots.
• Two heaters could be necessary for bigger aquariums or instances when the ambient temperature is considerably below the ideal water levels. To provide uniform heating, heaters should be placed at opposites of the tank.
• As temperature increases, the length of the heater tube is essential. The heating tube should, in essence, be the same height as your tank.
• Upon draining the aquarium, disconnect the heater to avoid it from overheating after it is no more immersed.
• Place the heater near the filter’s water outlet so that the heated water is dispersed across the aquarium by flowing water.

FAQs

Wrapping up

For example, goldfish and white cloud mountain minnows do not require a heater and are perfectly content with room temperature water. Dwarf freshwater shrimp, such as cherry or crystal shrimp, do not require heaters.

However, the majority of aquarium fish are imported from tropical locations where the temperature is substantially higher than the normal room temperature. They require temperatures ranging from 75°F (24°C) to 82°F (28°C). If maintained in water that is too freezing for them, they will perish. Every tank housing tropical fish must, therefore, have a heater.

A general rule of thumb when choosing a fish tank heater is to go with something that can output 3 to 5 watts per gallon. The ability of the heater to warm or regulate the temperature inside the aquarium is determined by its wattage.

Make sure the heater you’re purchasing is completely submersible; most are, but it’s always a good idea to double-check. The automatic shut-off functions are excellent. Once the water level in your tank declines or the temperature goes up too high, they will immediately turn off the heater.