The ACDC-PLUS features an internal battery and power cord, LED screen, and many run options, including a emergency backup mode. The AC-DC-ONE is a more affordable option that runs on D batteries and is meant to function as a backup air pump. Both pumps can be found below. Also, an air check valve should be used with all air pumps in the aquarium to prevent water from leaking out of the aquarium, the link to our air check valve is also below.