Quote from RC's tank of the month for this month. Small excerpt, you have to read the entire thing to get a good picture of how/why he is successful.
I try to keep my system simplistic. I last changed the water in my aquarium 3 years and 8 months ago. At that time, it was basically as I was setting my current aquarium up in September 2008. Since then I just add freshwater by pouring it into the aquarium. Every two weeks I use a calcium chloride additive to supplement calcium depletion. I also add magnesium chloride, magnesium sulphate, and sodium hydrogen carbonate (baking soda). These additives keep my calcium, alkalinity, and my magnesium at proper levels. Occasionally, I will add Lugols. I also add live marine phytoplankton at times.
Water Parameters:
Salinity: 1.026 (refractometer)
Temperature: 25 - 27