Essential Reef set up equipment

[ponokareefer]

Not exactly an essential item, but definitely nice to have is timers for your lights. You can usually pick them up at hardware stores for about $15 each.
You may also want to look at setting up some type of wavemaking device. There are a lot of different ways of doing this, so you may want to investigate them. I used 2 Koralia 3's with a Seio Electronic Powerhead Controller, and that has worked really well for me. The ultimate though is a Tunz Wavebox. You will be looking at $500 to $600 though.