Air pumps ideally need to be positioned above water level and with a non-return valve fitted. Some pumps will have a small bracket on the back to hang on the wall or it can be put on to a shelf. The air line can be cut and the valve fitted inline with the black part facing the air pump.  

Here we have provided an instructional video to help you visualise the set up:

Need any further assistance? Contact our customer services team who will be happy to advise you further.