I’m the type of hobbyist that likes to keep things as simple as possible while maintaining the best possible water quality that I can.  One of the more important parts of this is completing weekly water changes.  I have found that completing a weekly water change of about 10% to 20% works well for maintaining trace element that will be consumed by corals and coralline algae while helping to prevent a buildup of nitrates and/or phosphates in the water.  Depending on the amount and type of corals combined with the bioload of your fish, you can adjust the amount of your water change to have the same effect.  I have found the less supplements you have to dose, the more stable your water will be.  Weekly water changes allow me to achieve that without having to put a lot of effort and expense into dosing and testing trace elements.

The below links can add a little more details for you

http://www.reefaquarium.com/2012/mixing-saltwater/

http://www.reefaquarium.com/2013/the-basics-of-marine-aquarium-water-parameters/

http://reefkeeping.com/issues/2007-11/nftt/

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