Starting with the first step, here's how to change an existing basic saltwater FO/FOWLR aquarium into a reef tank system in 7 easy steps.
Step 1: Create a Tank Log
One of the most valuable tools a saltwater aquarium hobbyist can have for solving problems is an accurate and well kept log about their aquarium. There are a number of free for download aquarium maintenance software programs available that are easy to set up and use, and some of them even offer troubleshooting features.
Investing the few minutes it takes to record important statistics, such as water test results, equipment and other component changes or additions you made to your system, as well as taking note of your observations (i.e. water a bit cloudy; brown algae appearing) can pay off in a big way when you want to solve a problem, or are planning to make improvements to your system.