[jostafew]

I'm sure everyone will have an opinion about which controller system is best, and they'll all probably be right because their suggestion suits their own needs, and I'm no different hahah. I've got a DA Reef Keeper Light with an additional PC4 module running my reef managing heating, cooling, 4 stage lighting, and I have an alarm set to kill my MH in the event that temp rises beyond what my chiller will handle. I've considered adding a switch input module and float kits to handle ATO duties but my JBJ system was more cost effective so I run that instead. I think the RKL is a great value, starting with the controller, switch module and temperature probe for around $130 it's worth it just to prevent the thermostat in a $30 heater from turning your tank in to a sauna one day. In fact that's exactly why I'm going to use one on my upcoming nano build, not to mention that it will also handle my 2 stage LED lighting. I've had zero problems with my controller and it's two output modules in the two years that they've been running my system.

You mentioned PH monitoring, for about $100 on top of the RKL basic package you can add an SL1 module (if memory serves) and a PH probe (I think the American Marine pinpoint PH probe is cheaper). With that PH input you can monitor PH on the display and also use that as a control input to work with a Calcium reactor for eg. to cut CO2 injection if PH drops too far.

Also, DA recently announced that their Net module is now compatible with the RKL so you don't need the advanced controller to get network / web stuff.

I think the best thing you can do is to put together a wish list and then post that up here and look for comments. People who are familiar with their particular systems will be able to tell you what system and its accessories will handle what tasks, and then you can look at cost and ease of use for that system.