In general if they run and respond to the potentiometer knob on the black box, everything is working. Just be sure the potentiometer is returned to 100% before connecting to a controller. I have never used an Apex and we don't license, test or endorse 3rd party controllers so my knowledge of them is limited to what I have read on forums. I believe you need the adapter cables and a VDM module.
rvitko thanks for the info. I seems that the potentiometer is not working correctly as the pump will not slow down or speed up while turning it. Is there anyway I test with a meter ?
It could be the knob is just disconnected from the potentiometer, the head of it is basically a small philips screwdriver that inserts into the potentiometer. It could be the potentiometer is broken and we can then change the small board with the potentiometer. It could be something is wrong with the motor so it is always on a low power setting, this could be as simple as it is jammed up by calcium, especially between the metal shaft it spins on and the magnet of the prop. It could also be the motor is damaged in some way and would have to be replaced. While I am sure the resistance of the potentiometer could be tested as you turn it, I would typically just do this by trial and error and try a replacement if it was here, we would replace the entire small board in the junction block.