Detailed Guide on How To Heat a Betta Tank Without a Heater 2021

How To Heat a Betta Tank Without a Heater

Having difficulty on “How To Heat a Betta Tank Without a Heater“? Then don’t worry as this article will be a game changer for you!!

Today’s article is how to set up the tank without using a heater. To be clear, getting even a basic heater for your Betta is recommended owing to their temperature requirements, however if you’re not using one for any reason, these suggestions should suffice as a temporary remedy.

Betta fish require a continuous temperature of up to 80 degrees to keep fit and positive, and the only way to achieve this is to use a heater (25 watts heater in a smaller tank of 3-5 gallons as an example). I wrote this blog post for anyone who doesn’t have a heater but plans to buy one soon. It should work as a partial fix, but please buy a heater as soon as possible.

Detailed Guide on How To Heat a Betta Tank Without a Heater

Step one: Betta Fish Tank Without a filter, heater, CO2, or fertilizers:

Betta is commonly kept in a small bowl, however this does not guarantee that it is having a happy life, since betta in such a habitat might develop sick. Do not keep betta in a tank that is less than 5 gallons. It is best for betta if you utilize a larger tank.

Betta need freedom in the tank to swim and tunnels in which to retreat. It’s also a plus if you have real plants in your tank for this fish. Plants can change betta excrement (which is poisonous because it releases urea into the water) to nitrate (which is still poisonous and can kill fish) and then to nitrate (which is less harmful to fish and can be eliminated by changing the water on a regular basis).

As a result, plants serve as a natural filter for betta fish while also adding to the tank’s aesthetic appeal. Betta like resting on plant leaves and finds it more safe and pleasant to hide and relax among the plants. Plants may also offer betta with a natural habitat. Although a filter will keep the water clean, a betta tank without a filter, heater, CO2, or fertilizer is conceivable, and I will show you how to do it in this post.

Size Does Matter When Choosing Your Betta’s Tank:

A betta fish ought not be housed in a 1-gallon tank; at least 5 gallons or 20-liter tank is necessary. Bettas, in my view, require larger aquariums since they require more area to swim and larger tanks can have plants that function as filters. Small tanks are also not recommended since you won’t be able to regulate water quality since ammonia surges can occur very quickly. Also, if your tank is large, you won’t require as much upkeep. If the tank is highly vegetated, you may raise betta fish in a nano tank without a filter, heater, CO2, or fertilizers.


Betta fish are thought to be semi-aggressive, although each one has its unique personality. Some are violent and quarrel with their peers, while others are so placid that they are disturbed by their peers. As a result, I believe it is preferable to leave Betta alone. However, if you wish to keep other fish with your betta, you must observe your fish for three days and remove any new companions if you discover aggressiveness.  

No Heater:

You don’t need a heater if the water temperature doesn’t quite drop below 24 degrees Celsius where you reside. A heater is also unnecessary if the tank is kept at ambient temperature inside the house. Using a thermostat, keep an eye on the temperature of your tank.  

No Fertilizer:

Fertilizers that aid in plant growth are required if you want to maintain your plants healthy. Fish waste, on the other hand, may work as fertilizers for plants, and if you have fish in your aquarium, you won’t need any additional fertilizers because the wastes will be devoured by the plants. Betta fish excrement settles on the aquarium’s bottom, where it decomposes, releasing ammonia into the tank. Plants will use all of this waste (nitrate byproducts) to develop in the presence of sunlight, providing betta fish with a clean tank to dwell in.

No CO2:

Plants inhale CO2 in the same way as people do. Most tank plants do not require additional CO2 since the majority of the CO2 they require is exhaled by the fish in your aquarium. If you want to have bettas and plants in the same aquarium, I think a non-supplemented CO2 tank is a suitable choice.

Also Read : How To Setup Betta Fish Tank without Filter

Step 2: Without a heater, here’s how you keep Betta water warm

These are the 5 finest temporary alternatives that don’t require the usage of a heater.

Make Use of Your Hood/Canopy:

Using the hood or cover for the tank is one of the simplest methods to guarantee that your Betta water is and stays warm. Put a cover on your tank, in layman’s words. If you cover your tank with a lid, the heat will be retained better since it will not evaporate as quickly through the surface of the water as it would without one.

Yes, putting a cover on your tank will make reaching the inside a little more difficult, but most tops come off rather quickly, so it shouldn’t be too much of a problem. Furthermore, if you really are concerned about ventilation, you may always use an air rock in the tank. This manner, even if there isn’t much air in the tank, the air pebble will more than compensate for the shortfall.  

Make Use of a Brighter Light:

Making advantage of the lighting is also another approach to keep the water in your Betta tank warmer. Tank lights, at least some of them, emit a significant quantity of heat. Lights are useful not just for lighting, helping your Betta fish feel at home, and promoting plant development, but they may also provide some additional lighting.

A good light that runs for 8 or 10 hours a day will undoubtedly warm up the water. If the light you have now is insufficient, you may always increase the quantity of lighting for a short time. Nevertheless, you must be cautious of temperature swings when doing so, since when the light is turned off, the warmth begins to drop somewhat. It’s all about striking the right balance here.

Place it in a warm location:

Keeping your Betta tank in a warmer location is a simple approach to help your Betta tank water warm up without needing a heater. There’s a good chance that certain parts of your house are hotter than others. If you have a two-storey home, for example, the upper floor will normally be warmer than the bottom floor.

This can result in a temperature differential of a few degrees at the very minimum. Furthermore, if the tank is placed in a region with restricted airflow, there will be little wind to allow heat to drain from the tank. Finally, if you can locate a spot in your house that gets enough of sunlight throughout the day, you may put the tank there as well. When dealing with actual sunlight, you may need to take certain precautions to prevent algae outbreaks (see more about eliminating algae from your tank).  

Use a filter that is inefficient in terms of energy:

One technique to keep the aquarium a little warmer than it would be otherwise is to employ a filtration system that runs hot and consumes a lot of electricity. Non-energy-efficient filtration systems, for example, operate hotter than energy-efficient filters. The heat generated by the filter’s engine will help to warm up the water.

A Smaller Tank:

Although this is a double-edged sword, it still works. It takes longer for larger bodies of water to warm than smaller bodies of water. As a result, if your Betta tank is small, it will warm up even faster. It can be hard to master this solution. Also, as the smallest tank size, we would not suggest anything less than 3 gallons.  

Your tank’s glass walls should be insulated:

After you’ve gotten your tank’s water temperature to an appropriate range for the fish you want to keep, insulating the glass walls is a good next step to think about. While utilizing Styrofoam to cover the back and side panels of the tank is not always the most aesthetically pleasant choice, insulating film or foil is a close second. This strategy will prevent the heat from leaving, but you may need to conduct warm-water swaps on a regular basis. This is the practical disadvantage of not using a heater in an aquarium.  


Whether you want to or need to, there are many of effective ways to keep a fish tank warm instead of using a heater. It’s up to you to determine if the burden of maintaining this configuration in the long run is worth it. As you can see, there are a variety of alternative fixes you may use to keep your Betta fish tank warm without using a heater. We strongly advise you to buy a heater for your Betta tank as soon as possible; it is critical, in our opinion, to guarantee that your Betta is healthy and has the proper living circumstances.   


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