Well I don't gonna tell you what Apex can do cause can do a lot just gonna tell for example what my is doing

I have two temp probes one in my tank and second one in the sump apex is monitoring the temp all the time (chiller heater)... Of course pH monitoring, ORP and salinity, it controls my led cannon pendants sunrise - sunshine etc. my MP60w ES is connected to the apex and that's the best IMO module I've ever got... I have programmed different pump cycles during the day and night and don't have to touch pump controller.
Lunar simulator is also connected to the Apex

But the main part of those gadgets is security... Leak detector in the cabinet ( I had situations when my skimmer filled the collection cup and splash water outside sump now detector is shutting off the skimmer if it feels any drop of water) ATO directly from RO filter using solenoid valve, skimmer water level security, if the durso pipe gonna flake (happen to me few times cause is not glued into the bulkhead in overflow) and all water from overflow gonna drain down to the sump the water level gonna raise up and all dirty stuff from collection cup gonna go back to the system - no more 1/2" higher and apex is turning off the skimmer...
Water level in the overflow if something gonna get stuck in the drain line apex will turn off the red dragon, plus (one of my favorite) I have several programs for feeding/maintenance time. For water changing I need 45 min so apex is turning off skimmer, all circulation pumps, main pump and whatever else you need, same when I need to direct feed my corals

Friend of mine has daily water change program and apex is draining 4 gal of water from his tank and pumping back fresh mix...
Anytime something is going wrong I'm getting text message and email...
I really like this gadget
Regards,
mark