are all about maintainence. Dispite rumors that they are obsolete and outdated they are still commonly available at most retailers and are generally the most common type of filter sold as part of a set-up in Mom and Pop stores. If you maintain proper maintanence and run them correctly they maintain water quality just as well as a HOB
or canister filters. I have used them for over 20 years on cichlid tanks, never have issues with water quality, and don't use any HOBs or canister filters in combination with them. IMO
, they are far cheaper and far easier to maintain than either of the other types of filters. They do have their limitations however, and the most common fail is lack of maintanence. You can keep some plants with them, but the roots do grow through the plates and on a heavily planted tank impede water movement. They do not work with sand, only gravel, and they don't work well when water movement is driven by airflow. To be fully effective, you need to combine the UGF
with mechanical water movement (powerheads). If your not will to do regular gravel vaccing, they are not the filter for you.