Below we will outline aquarium conditions that are ESSENTIAL to your betta's health and survival. These are the fundamentals of betta care, and all of these rules should be followed.


Beyond that, we will also provide IDEAL suggestions for how you can make your bettas life the best it can be, by tailoring the envuronment to their specific physical and behavioral needs. 

  • If you betta is hiding or acting strangely, and you've ruled out illness, you may want to review the Ideal suggestions to see if there is an environmental stressor that you can eliminate to make your fish happier.



ESSENTIAL: Bettas must always have access to the water’s surface to breathe air from, and so tanks can’t be filled to the brim.

  • If a betta is prevented from reaching the surface, it will suffocate as its gills alone cannot obtain from the water all of the oxygen that the fish requires. The fish must also be able to gulp air from the surface of the water, which air is then processed by the specialized labyrinth organ. (for a description, please see ANATOMY)



ESSENTIAL: Bettas require a tank with a full lid to prevent jumping.

  • •Bettas are very capable of jumping out of their tanks to their death if given the chance, and medium-large openings in tank lids should be sealed off, possibly by packing with filter sponge or another inert, non-toxic material, so that a betta cannot jump out through them.

IDEAL: A full, sealed aquarium lid also promotes respiratory health.

  • A betta's native habitat is very warm and humid, and a full tank lid creates a layer of warm and humid air at the water's surface. This is the air that the betta will breathe through their labyrinth organ, and it needs to be warm and moist to maintain the health of this organ.
  • A tank without a lid will result in air at the water's surface that is too cold (relatively) and too dry for a betta.



ESSENTIAL: Bettas require water that is heated to between 76-82F.

  • "Room temperature" water is not acceptable, as this may vary widely with the season, placement of the tank (ie: near windows/drafts) and geographic location, and in many climates, a betta kept in room temperature water can freeze to death, especially over winter. Tanks should not be placed in direct sunlight, or in drafty areas which might cause temperature fluctuations.
  • Lights are not suitable as a means of heating a tank, as they would either be left on for 24 hours, maintaining a more stable tank temperature, but effectively destroying the betta's natural day/night cycle, or they would be turned off at night allowing the temperature to fluctuate up and down greatly as the light is turned on and off.
  • Since bettas are cold blooded, as are other fish, they are able to slow their metabolisms down to survive in cold conditions, like room temperature water, but this comes at a large cost. Their immune systems are compromised and they will be much more vulnerable to diseases, especially fin rot, which can quickly eat away at their fins and can be stubborn, difficult to treat, and can become a fatal infection of the fish's body. Also, as their metabolism slows, so does their digestions, greatly increasing the odds of constipation/impaction and further related problems.
  • The best treatment is prevention - maintaining your betta's tank at a steady 76-82F with a heater



ESSENTIAL: The water in a betta’s tank must be filtered to remove toxic ammonia.

  • Any amount of ammonia is toxic to bettas, as it is to all other fish.
  • Betta’s constantly produce and excrete ammonia as a by-product of metabolism (somewhat like urine)
  • Ammonia will steadily build up in your betta’s water unless you take steps to remove the ammonia, both by doing water changes and adding a filter
  • See our page on FILTRATION for a list of ways to keep your bettas water clean and safe.
  • Water changes can also help to control ammonia, especially in an emergency where the ammonia in the tank is high, as the fresh water replaces some of the ammonia-rich water from the tank.

IDEAL: Bettas generally do not like strong currents, preferring gentler/slower filters.

  • Originating in relatively still water and having long, flowing fins, bettas are not the strongest swimmers.
  • A filtered, cycled tank is ideal for a betta, as it is for other fish, but steps should be taken to reduce strong filter currents so that the fish is not pushed by them. Placing plants underneath the filter output will help to break up the flow, and various baffles can be fitted to faster filters using filter sponge or a well cleaned pop bottle. If the tank will be filtered but not cycled (such as a small 3-5 gallon tank that is difficult to cycle) it may be useful to add an ammonia absorbing filter insert to control toxic levels. Ammonia and nitrite levels should be tested regularly to ensure that they stay in the safe range (ammonia and nitrite should be 0, and anything over 0.25PPM for either is highly toxic)
  • If you see your betta being tossed around in the tank by the current, you may want to make a change to help him out!
  • Bettas can be kept in tanks that are not filtered, though a filtered, cycled tank is ideal, as it is for all fish. In the case of an unfiltered tank, ammonia should be tested more frequently and larger and more frequent water changes should be performed to prevent ammonia from building up. If ammonia levels can not be kept at safe levels for the fish (well under 0.25PPM), a filter and/or ammonia absorbers should be added.

IDEAL: Suction created at the filter intake may catch and tear a betta's delicate fins.

  • To remedy this, you may need to attach a piece of foam or a nylon stocking to the filter intake.
  • For inspiration, see our tutorial on MAKING A SPONGE PRE-FILTER, and for  a description of the parts of a filter, visit our FILTRATION page



IDEAL: Bettas may prefer lower light. Their native rice paddies are densely filled with plants, providing shade, and the waters are often tinted brown, like weak tea, from the tannins of fallen leaves. For this reason, bettas may not like situations of very high, bright light for extended periods.



ESSENTIAL: Bettas must be provided with tanks large enough to allow them to swim around (we recommend a minimum of 5 gallons)

  • Contrary to popular myths, bettas are not lazy or sedentary fish. A betta that sits on the bottom of its tank all day is either unwell or unhappy. If your betta is behaving this way, it should be an immediate cause for concern and investigation.
  • It has been suggested that the leading cause of premature death in bettas is fatty liver disease resulting from inactivity and overfeeding.




ESSENTIAL: Bettas easily snag and tear their fins on rough plastic/edges of decorations, leaving injuries that are vulnerable to infection. Their fins are a membrane only a few cells thick and are very delicate. Plants and decorations should be checked for sharp edges before they are put in a betta tank, and real or silk (fabric) plants should be chosen over plastic.

  • A good test of a decoration’s suitability for a betta is lightly dragging a silk stocking over it. If the stocking snags or sticks, the decoration is not suitable.


ESSENTIAL: Being very curious, bettas can get stuck in small holes in decorations while trying to explore. This can result in injury or even death. Small openings that a betta could become wedged in should be sealed (possibly by packing with filter foam or sealing with aquarium silicone).

  • River rocks/stones used as substrate may create small crevices (see above problem) and may not be suitable for that reason


IDEAL: Bettas may be more comfortable in densely planted/decorated tanks.

  • The Thai rice paddies that bettas are native to are filled with dense plant growth. As a result of this native condition, bettas may be uncomfortable in tanks that  are sparsely decorated or do not have a lot of hiding spaces
  • Contrary to popular myth, bettas are not uncomfortable in large tanks. They may, however, be uncomfortable with large, open spaces. Providing an additional plant or piece of decor can make all the difference.



  • WARNING - Bettas are viciously territorial fish who will fight to the death. Two male bettas must never be kept in the same tank without a divider between them, nor should a male and a female. When placed together, two males will display to each other and eventually fight. Spawning can also be quite violent, and a female will eventually be attacked by an amorous male if she is not ready to lay eggs. In the wild, one fish can flee a dispute with another, but in an aquarium, there is nowhere to run and one betta, or both bettas, will end up injured or killed.
  • Some female bettas can be kept together in “sorority” tanks, but must be watched closely as bullying and deadly conflicts can still result. Females can be as aggressive as males. When adding females to a sorority tank, they should ideally be added at the same time, so that no fish has established a territory within the tank that they will try to defend from a newcomer. No less than 4 females should be kept together, as this will spread out the aggression, and 6 or more females may be best (but be careful not to overstock your tank).
  • Depending on the individual betta’s temperament, some can be kept in community tanks (one male, or one or more females).

Bettas should NOT be kept in tanks with any of the following:

  • Species closely related to bettas, such as gouramis. These fish often show similar territoriality to bettas and conflicts may result;
  • Brightly colored fish with flowing fins, such as fancy guppies, as bettas may confuse these fish for other male bettas and will attack them;
  • Fast moving and/or aggressive/nippy fish, such as danios. Bettas are not the strongest swimmers and may either be harassed by these fish and unable to get away, or unable to compete with faster fish for food.