I've not updated my Profilux 3ex for years. I'm using 5.0.3.2.
It works, although to be honest I've been very lazy and hardly ever make changes or check readings. Basically I use it to control lighting on a large (3,000l) reef. I'm re-energised and would like to start using the system more thoroughly (eg re-connect the dosing pump, control more operations, put in feeding pause on pumps etc). I would especially like to access and control the system from my iPhone if possible.

My questions therefore are:

Should I upgrade the software? (if so can I go straight to the latest version or do I need to do it in steps?)
Looking at the site there is reference to GHL Control Center and Profilux Control. I'm only familiar with Profilux Control. Should I familiarise myself with the former?
Having not kept up with changes to the system over the years, are there any new probes available? eg Nitrate or Phosphate?

thanks all!