According to relevant information, here is a comprehensive guide on selecting the best fish tank for betta fish:

1. Fish Tank Size
- For single betta keeping, recommend a square tank of at least 15×15×20cm.
- The minimum size should not be less than 12cm. A 10cm tank will lead to insufficient activity space and difficult water quality control.
- Chinese bettas prefer 20×20×25cm tanks, while Thai bettas need at least 15×15×15cm.
2. Material Selection
- Super white glass is optimal: It offers high light transmittance, durability, and excellent aesthetics.
- Acrylic is a secondary choice: Lightweight but prone to scratches and aging.
- Avoid round tanks: They cause visual distortion.
3. Functional Design
- Suggest tanks with anti-jump lids.
- Adding black background paper can enhance visual appeal.
- Multi-compartment designs are ideal for breeding or preventing fights.
4. Supporting Equipment
- Use a sponge filter instead of a traditional filter (strong water flow affects bettas).
- Add Indian almond leaves to create slightly acidic water.
- Maintain the water level 3-5cm below the tank top.
5. Popular Recommended Models
- Super white glass: Biansheng Super White Glass Betta Tank (20cm size).
- Multifunctional: Duchongni Desktop Ecological Tank (with LED light and filtration system).
- Budget-friendly: Building Block Tank (15.5×10.5×12cm).