Do bettas need a heater?

In most cases, the answer to “Do Bettas Need a Heater?”, will be yes. Read on to find out why.

betta heating

What temperature should a betta tank be?

In the wild, bettas live in south-east Asia. In other words, a place with a very warm, tropical climate.

Bettas are hardy fish and thrive happily between 78 ℉ to 82 ℉. This is something to remember when caring for a betta. Chances are you’ll need to heat your aquarium as usually a house will sit at room temperature (70℉), which is too cold for a betta to stay healthy.

The water temperature for a betta should never drop below 74℉.

Aquarium Heaters

Aquarium heaters are a submersible tube-like instrument used to keep a constant, adjustable aquarium temperature. Some heaters are also manufactured to give a pre-set temperature, rather than have an adjustable option.

The pre-set heaters tend to be cheaper compared to adjustable heaters, and the nano pre-set also tends to be more reliable for keeping a consistent temperature too.

They can be placed or stuck onto the side of an aquarium or they can sometimes be inserted into the filtration compartment of a nano / compact aquarium. They can range in size.

It wouldn’t be difficult to find one to fit the size of your betta aquarium. An important factor to consider is the larger the volume of the aquarium, the higher the watt the heater should be. A good measurement to follow is one watt per litre (or 5 watts per gallon).

To put it simply: a 15 watt heater would not be able to heat a 30L aquarium substantially for a betta, even with an adjustment dial. Something like a 25 watt heater for a 20L would be fine – perfect even.

How to set up an aquarium heater for a betta

Instructions will usually be given on the heater box, but setting one up for an aquarium is fairly straightforward; simply submerse it in the aquarium.

If the heater has suction cups attached, you can anchor it to the wall of the aquarium. There should be a dial somewhere on the heater to allow you to adjust the temperature. For a betta, set the temperature to about 78℉.

It may take time for the heater to start up, then it takes time for the aquarium water to reach the given temperature. Check the temperature with an aquarium thermometer (these are easy to come by and inexpensive).

Once the water reaches 78℉ it should stay at that temperature, give or take.

Be sure to check the temperature regularly. The aquarium may change temperature slightly from time to time depending on the environment it’s in, e.g a house in a country where the seasons vary in temperature a fair bit.

Also, the heater may break, stop working or turn off for whatever reason. Over time heaters tend to deteriorate.

We have a digital thermometer for our aquarium that constantly displays the temperature; we check the temperature whenever we look at the aquarium, just out of habit.

A note about aquarium thermometers

As mentioned, you can grab an aquarium thermometer for a low price. Sometimes you can get stick on ones, a submersible mercury thermometer or even a digital one.

The more expensive ones usually give a more accurate measurement, but as long as you can clearly see the temperature of your aquarium is sitting between 78℉ and 82℉, you don’t need anything fancy.

Which heater do we use?

For the Fluval Spec 19L that houses our betta, Naan, we purchased a (Aqua One – 25W Nano Heater).

This was easy to install and works nicely. This nano heater doesn’t have a dial to adjust temperature but is preset to heat to a temperature of 78℉. The 25W is perfect for or 19L fluval and keeps aquarium at a temperature of 78℉.

Other heaters that you may like to check out

You can get heaters that either have an adjustable temperature, with a dial, or heaters that are preset to warm up to a given temperature. The heater mentioned above (the Aqua One – 25W Nano Heater) is preset to heat to 75℉ – perfect for a betta in a 20L aquarium.

Here are some other small heaters that we recommend:

The Hydor Theo

The is a reliable heater, super reliable. Some nano heaters can keep a temperature than can change up or down by a few degrees depending on the environment, which isn’t too much of a problem seeing that the temperature always sits between 78℉ and 82℉.

This heater will keep a constant temperature by turning on and off with no spikes. It comes with a dial, allowing you to select a desired temperature, so in this case you’d turn the dial to about 78℉.

Adjustable, reliable. Check it out on Amazon here.

Fluval Marina Submersible and Submersible Mini

Again, a reliable heater, the nano is only available in 50W. It comes with a pilot light to indicate if the heater is on or off – the heater will switch itself on or off to keep a consistent temperature. It also comes with an adjustment dial to set a specific temperature.

Check the Mini out here on Amazon

Aqueon Pro Submersible

This is only available in 50W or above, it’s a great little heater, though. Maybe not as reliable as the others mentioned, it will keep a somewhat constant temperature but may not always achieve the desired temperature.

It comes with an adjustment dial, so for example if you set it to 78℉ the aquarium will likely run at 76℉ to 77℉. It’s therefore best to set it a degree or two above the desired temperature. It turns on and off to stabilise the aquarium temperature and has a pilot light to indicate so.

This heater is known to durable, long lasting and shatterproof – unlike the other heaters listed, this isn’t made of glass.

Check out the Aqueon Pro Submersible here on Amazon.

Does my betta need a heat mat?

It needs some sort of heating apparatus. Generally, heat mats aren’t used for aquariums. It’s usually not a good idea as they don’t tend to be waterproof and don’t come with an adjustable temperature.

We’ve seen that external aquarium heaters are on the market, with even Zoo Med selling a betta bowl heat mat, but it’s best just to stick to a standard aquarium heater.