Bettas, unlike other species, are not schooling fish and will fight with each other, regardless of gender. Bettas prefer to swim alone and also need a comfortable place to hide. Aquatic caves or dense, planted corners work great in making a betta feel safe.
When cleaning a betta’s tank or bowl, make sure you only take out a third of the water each time and replace it with fresh water. This will gently allow the fish to adjust to the temperature and pH of clean water – while not upsetting the biological balance of the fish’s environment. This should be done about every three or four days for small bowls or tanks. If your water has a high level of chlorine in it, you may need to add a drop of declorinator to the tap water before adding it to the tank or bowl. And never use soap or disinfectants to clean off fish ornaments or decorations. This will harm the fish. Plain warm water will work just fine for cleaning these items. You can also use a small turkey baster to siphon debris from the bottom of the tank. This will prevent excessive ammonia and bacteria from building up.