When the lights are on, the CAP switches on two outlets labelled "exausts" when your humidty or temp raises above their set points. I have an aircon plugged into these sockets. One would assume that you only need heat when the lights are off. There is a single "nightime" outlet that you could plug your heater into that would trigger the heater to come on at night.
My dehumidifier has a humidistat on it where I can set the humidity so I just have it plugged in to the wall socket and it's always on. It is important that your devices that are plugged into any timer or the cap automitically revert to your settings when they receive power.
Example: you set your heater at 75 when it's on then turn it off. When you turn it on again, it goes directly to that 75 setting. When my aircon receives power it automatically starts and goes to the predesignated settings.
If your heater and aircon have built in controllers there is no need for the cap controlls but I use it because the unit sensors are closer to the plants then my aircon sensor is.
If you don't have aircon and are using vent fans to cool then the cap is neccessary as it turns on the fans when the peak temp is reached and turns them off when it's about 3 degree lower than the temp. The great feature is that when the vent or aircon is turned on, it stops dispensing co2 until they turn off.
A ppm co2 controller is around $400-500. For the extra couple hundred you get an integrated controller that manages your whole system. If your not concerned about maximizing yield and your not going to use co2 then the xgc1 is not needed. If you ate going to use co2 then the xgc1 is the best value by far. I did a metric shit ton of research before buying mine
hope this helps and thx for the rep.....