The next type of fish filters that you can buy are the under gravel filters or UGF
The next type of fish filters that you can buy are the under gravel filters or UGF. These fish filters are made to fit in the bottom of your fish tank. There is an inch or two of gravel that is place on top of these filters. These under gravel filters are connected to an air pump or a power head. You should be careful that you never just turn off an under gravel filter. clean tank is important for the proper care for betta fish, and using the right filter will ensure a healthy happy fish.