Well, no actually. It comes with 8 programmable outlets. The only "add-ons" I bought was a feeder, and I added an orp probe (just plugs into existing port), to control my ozone. I run my ato, skimmer, return pump, circ pumps,tank lighting, sump lighting, air pumps, heater fail safe, ozonator all without buying "extra" modules. I also have sump high level alerts, skimmer collection tank high level alert/control, rodi and kalk resevoir low alarms etc.....sent to my phone via text....all without adding any extra modules....just float switches. Out of the box you can pretty much automate your entire system (I travel for a few weeks at a time regularly so this is extremely convenient for me). I can monitor/control any aspect of my tank from anywhere in the world from my smartphone....including changing programming if I like, from anywhere.
I also hat to admit, I wiped out my tank twice with fresh water. First time forgot I was topping up the tank and went to bed with the manual tank fill open.....all night. Next day I created an auto top off with failsafe with just a couple of float switches. 2nd time my skimmer went nuts, overflowed all night onto the floor, makeup kept running fresh water into the tank. 20 minutes to wire a float switch into the skimmer overflow resevoir to send alarm/shut off skimmer, and that won't happen again. The peace of mind when I travel is worth every penny to me.
Cheers