I just had a brain fart . . . The PM2 module might be needed to run a pH probe on the Apex junior.
And, to echo what intarsiabox wrote, whatever devices you want to control will need to be plugged into the controller's outlets. You may not want to control everything, so you may be able to leave some things plugged into your existing powerbar.
Edit:To give you an idea, here is an Apex Lite with two powerbars, the display module, a breakout box, and a VDM module.
Everything that plugs into that is controllable.