Premium Fish Tank Filter Material

What type of filter is best for a fish tank?     Upper filter: The upper filter literally means the filter system placed on the top of the filter media for fish tank. The working principle of the upper filter is that the water pump draws the water into the filter tank, and then flows back into the fish tank from the water outlet pipe at the bottom through various filter materials, filter cotton, etc. in the fish tank filter material.      Advantages of the upper filter:     1, The price is reasonable.     2. Convenient for daily maintenance.     3. Good physical filtering effect.     4. There is no need to set up a separate space for placement.     External filter: The external filter is to hang the filter device on the side or above. The water is pumped into the fish tank filter media with a submersible pump, filtered through…