Welcome!! Glad to see you on here!
Edit: In regards to controllers, they are not necessary per say, but they are very helpful. You will find many reefers that have been very successful, and do not use controllers. These people just utilize outlet timers or power strips with built-in timers, job-specific monitors (PH, Temp, Etc... Look up Pin Point Monitor for an example), and power centers (such as DJ power strips). On the flip side, you will find many who will not run a tank without one (like myself). They provide you the ability to completely control the mechanicals of your system, as well as monitor parameters such as PH, Salinity/Conductivity, ORP, Etc...
I suggest you visit the following manufacturer websites to learn more about controllers before you jump in:
http://www.neptunesystems.com/">http://www.neptunesystems.com/</a>
[IMG]http://www.digitalaquatics.com/">http://www.digitalaquatics.com/</a>
[IMG]http://www.reefangel.com/">http://www.reefangel.com/</a>
IMO, The Netune Apex is the best of the group, but it really comes down your own preferences when selecting one. The Neptune system is more of a plug and play system that has great support. The Reef Keeper system is very similar, but after having one for a while, I felt that their support and software updates were lacking. The Reef Angel system is a quality system as well, just not as popular as the other two. This is at least my 2 cents, I am sure many others can provide you with better/more information. Welcome to the forum and I hope that the skimmer serves you well!