If you’re tempted by the thought of starting an aquarium, keep in mind that you will be putting yourself in charge of beautiful, precious living creatures. Here are some things to keep in mind. Age: For children, starting small and letting the hobby grow with them can develop into a lifelong passion and appreciation of nature. For adults, along with the responsibility of keeping things alive, is the opportunity for artistic expression, scientific investigation, understanding the mechanics of pumps and water chemistry and, if you choose, an expanded community of likeminded friends. Responsible sources: When choosing fish, investigate how specimens are obtained, and try to do business with environmentally responsible sources. Books: A book King suggests as a great reference and has found useful since his high school days, now out in a 2008 updated version, is The Conscientious Marine Aquarist: A Commonsense Handbook for Successful Saltwater Hobbyists by Robert Fenner, Matthew Wittenrich, and Scott Michael. (TFH Publications, about $61 from Amazon.ca.) Another book, now out of print but worth searching for at used book sources, is Natural Reef Aquariums: Simplified Approaches to Creating Living Saltwater Microcosms by John Tullock (TFH Publications).