This instructable covers certain aspects of building an aquaponic system. he uses an arduino micocontroller to regulate the frequency of system cycling.
Before you begin building you need to determine a few parameters which will help you select appropriate tank/pump and grow bed sizes etc.
Your driving criteria maybe fish yields, plant yields, space limitations or other. Decide what kind of requirements you need to fill and base your design around those. For my system, it was simply to be an experiment as a pre-cursor to a larger system.
It takes time for the system to reach an equilibrium. 4 full weeks of cycling may be required to allow the system to build up a culture of organisms to reach stability. Before this time, you may loose fish and plants. Check the system regularly during the early stages of the systems life. Use aquarium bought chemical indicators to monitor the concentration of nutrients in the system and make adjustments as required.