Whether a betta fish needs an airstone should be determined based on its physiological characteristics, living environment, and specific needs. In general, there is no mandatory requirement to use an airstone, but it may be beneficial under certain conditions. Below is a detailed analysis:
I. Respiratory Characteristics of Bettas
Bettas belong to the family of Labyrinth Fish. Their gill structure is unique—apart from breathing through gills, they can also take in oxygen directly from the air using the labyrinth organ (located above the gill cover). This trait allows bettas to survive in oxygen-poor environments (such as small stagnant water bodies) and even breathe briefly out of water.
II. Criteria for Determining Whether an Airstone Is Needed
1. Situations Where an Airstone Is Unnecessary
Small-container keeping: If a betta is kept alone in a small tank (10 liters or less) or a betta-specific container, with clean water and an appropriate temperature (24-28°C), an airstone is usually not needed. Bettas can obtain oxygen directly from the water surface via their labyrinth organ.
Low-density keeping: When a single betta or a small number of bettas (e.g., 2-3 individuals) are kept in a larger container with gentle water flow, the natural dissolved oxygen may be sufficient.
Preference for stagnant water environments: Bettas are native to stagnant water environments like rice paddies and swamps. They are sensitive to water flow, and strong air currents may cause them to experience stress.
2. Situations Where an Airstone Is Necessary
High-density keeping: If multiple bettas are kept together or in a small container (e.g., 5 liters or less), the dissolved oxygen level may be insufficient, and an airstone is required to assist in increasing oxygen.
High-temperature environments: When the water temperature exceeds 28°C, the dissolved oxygen in the water decreases significantly, and an airstone can supplement oxygen.
Water quality deterioration: If there is an excessive amount of organic matter in the tank (e.g., failure to change water in a timely manner), microbial decomposition will consume a large amount of oxygen, and an airstone can alleviate oxygen deficiency.
Special breeds or health issues: Some artificially selected breeds (such as long-finned bettas) or weak/sick individuals have weaker respiratory capabilities and may require additional oxygen supplementation.
III. Alternatives to Airstones
If you prefer not to use an airstone, you can maintain dissolved oxygen levels through the following methods:
Regular water changes: Replace 1/3 to 1/2 of the water weekly to keep the water clean.
Increase water surface area: Use a wide-mouthed container to expand the contact area between water and air.
Grow aquatic plants: Plants like water lettuce and hornwort release oxygen through photosynthesis.
Use a filtration system: A small waterfall filter or sponge filter can slightly increase oxygen levels while maintaining water quality.
IV. Precautions for Using an Airstone
If you decide to use an airstone, keep the following in mind:
Choose a quiet airstone: Avoid noise that may disturb the betta.
Control air flow intensity: Use a regulator to adjust the bubbles to a fine and slow state to prevent excessively strong water flow.
Avoid direct blowing: The air stone should be placed away from the betta's resting area to prevent the fish from being hit by the water current.
Summary and Recommendations
Single betta + small tank: No airstone is needed; simply keep the water clean.
Multiple bettas / high-temperature environments: It is recommended to use an airstone or alternative oxygen-increasing methods.
Observe behavior: If a betta frequently surfaces (swims to the water surface to breathe), it indicates oxygen deficiency, and immediate oxygen supplementation is required.
Bettas have strong respiratory capabilities, but reasonable control of the keeping density and environment is crucial. An airstone is not a necessity, but it can serve as an auxiliary tool to deal with special situations.