you can hook up anything to any controller. Apex is the most open platform. plug whatever you want into it. Program it. You are ready to go. It is the least user friendly. You need to write code to use it(simple coxde), but it intimidates some people.
I have personally used a reefkeeperlite. That can run anything you need. PH, orp, temp, wave maker, etc.... The price tag is lower, but it can escalate quickly depending on what you add. you cannot just plug a PH probe into the main unit. you need expansion gear called an SL1. (scientific lab 1). It is basically a box that lets sends data to the head unit it can understand. I used it to control the pH of my calcium reactor, temp monitoring and controlling(halides off if temp is too high), and turning my lights on and off. It will measure power consumption sent through the units. you can control whatever with the power strip that comes with it, but you only have a few plugs. it is expandable but costs extra.
The reefkeeperelite or whatever the premium one is just handles more inputs or whatever than the lite. you can run most of a store off an elite. as a personal user you should not need more than a lite.
if you are only running basic stuff, then the lite is the way to go. It is user friendly, cheap, and effective. If you want every bell and whistle on your tank, then you should go with the apex so you can plug in every probe known to mankind without purchasing huge amounts of accessories. the Reefkeeperlite can run all that stuff, but it is easily as expensive as an apex by the time you buy all the addons
