If they are set at different times you would need 3 timers. There are 2 heavy duty outlets on each one but they are both turned off and on at the same times.
A controller will operate many of the items in an aquarium all from one place. It has a display with temperature and PH readings and also has a power strip where each outlet can be turned off or on independently. I just set up mine with 3 different stages of lighting and moonlights too. So that is 4 of the 8 outlets filled. The other outlets control things like a calcium reactor and my heaters and skimmer.
You can turn things off and on based on time, temperature or PH so you can control a lot of things.
The one I ended up using is an AquaController Jr by Neptune but there are lots of types available. There's a good page that someone built that compares all controllers in a graph. It is
www.aquariumcontrollers.com
You can't have a reef tank for too long without considering the ~$300 investment to be well worth the money. It will save you money and time. Some units also have built in web servers so you can check your tank from any internet connection in the world.
One of the coolest things about the controller is that you can tell it to turn on a fan if the temp gets too high, then turn off some lights if it gets past another temp, and finally turn off all lights if it continues to climb. You can also use it for running a chiller if you find that you need one.
If you consider the cost of buying 3 or 4 timers, a ph monitor or controller and a temperature controller you can see that the aquarium controllers are a pretty good value.
