Setup Betta Fish Tank With No Filter

2513 Imported from a malfunctioning feed
edited March 5 in Advice Tutorials

How to setup beta fish tank with no filter, heater, CO2, fertilizer:

Many people think that betta fish is able to live in small aquariums or bowls & they do not need large environment. Also they think that people keep bettas in bowls or vases which means they do not need clean tanks. However, those are misconceptions because bettas need more space to swim & need a clean oxygenated aquarium. To oxygenate water & keep it clean, you will need aquarium plants.

Betta Fish Aquarium
Betta Fish Aquarium

A filter will keep the water clean but a betta tank without a filter, heater, CO2, fertilizer is possible and I will share in this article how you could setup a betta tank with low tech.

Tank Size:

Betta Tank Size
Betta Tank Size

A betta fish should not be kept in a 1-gallon tank; size should be at least 5-gallon or 20 liters. In my opinion, bettas need larger aquariums because they need more space to swim & bigger tanks can hold plants which can act as filter. Also little tanks are not preferable because you won’t be able to maintain water quality because ammonia spikes can happen very rapidly. Also you won’t need more maintenance if your tank size is big. You can keep betta fish in a nano tank without filter, heater, CO2 & fertilizers if the tank is heavily planted.


Betta fish are considered semi aggressive but every betta has its own nature. Some of them are aggressive & they fight with mates but others are so calm that they are stressed by mates. So in my opinion, it is better to keep betta alone. But if you want to keep other species with betta then you must notice your fish for 3 days & remove the new mates if you see any aggression. Listed below are fish species that can hopefully live in peace with betta.

Betta Tank Mates
Betta Tank Mates

  1. Mystery Snails
  2. Ghost Shrimp
  3. Feeder Guppies
  4. Cory Catfish
  5. Harlequin Rasbora
  6. Neon Tetras
  7. Ember Tetras
  8. Clown Plecos
  9. Kuhli Loach

No Filter:

No filter in betta aquarium
Plants act as a natural filter in betta tank

Bettas need an environment that has enough oxygen & you can add live plants which will help you in achieving this objective. Also you need to do regular water changes if you are not using any tank filter. We recommend a 40% water change after every 3 days in a no filter aquarium. Also filters can make a water flow which is very harsh for bettas.

In order to have a betta fish tank setup with no filter, no heater, no CO2 and no fertilizer, the tank must be kept at room temperature and it should be heavily planted.

No Heater:

No heater betta tank
No need of heater if tank is kept at room temperature

If you live in a place where water temperature does not fall below 24 degrees Celsius then you do not need a heater. Also if the tank is kept inside the house at room temperature, then a heater is not required either. Monitor your tank temperature using a thermometer.

No Fertilizer:

Betta waste is fertilizer for plants
Betta waste is fertilizer for plants

If you want to keep plants healthy then you will need fertilizers which can help them grow. However, fish waste can act as fertilizers for plants & no external fertilizers are required if you have fish in your aquarium because the wastes are consumed by plants.

Betta fish waste settles in the substrate of the aquarium where it is decomposed and release ammonia in the tank. In the presence of light, plant will utilize all this waste (nitrate bi products) to grow and in return give betta fish a clean tank to live in.

No CO2:

No CO2 betta tank
Plants inhale CO2 expired out by fish

Just like humans breathe oxygen, plants inhale CO2. Most of the tank plants do not need extra CO2 because most of CO2 they require is expired out by fish in your aquarium. If you are planning to keep bettas & plants in one aquarium, then in my opinion a no supplemented CO2 tank is a good option.
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