All aquariums rely on water parameters. The basics are Ammonia, Nitrite, and Nitrate during the initial cycle. Plenty of info out there concerning the "Nitrogen Cycle." In the coral world (reef tanks) after the cycle is complete you'll spend time monitoring Nitrate and Phosphate for basic health. For coral growth and propagation, you'll monitor Calcium, Alkalinity, and Magnesium. Sounds like a lot of science, but I'm far from a science guy, so don't read too much into it. Get decent test kits (API kits are basic versions, there's better out there, but they function well). Do your water changes, and most things will stay pretty well in line. If you take the time to setup your system correctly from the beginning, you'll have a much easier time of it down the road. That means correct lighting for what you want to grow, correct amount of water flow, and ways to remove wastes from the water column.
There are two ways to add a sump to a system: Drill the tank or use a HOB overflow. Both ways will get water from the tank to a remote sump. Once the water is in the sump, you can do several things with it. Heat it, skim it, polish it with carbon or GFO, and/or feed it with macro algae. Then you'll put a pump in the sump that will return it back to the display tank. The benefits of a sump are aesthetic (you don't see all the gear in the display tank) and functional (you increase the amount of water in your system which helps stability).
Hopefully that doesn't create more confusion.
Mac
