I Hope this helps someone as much as it helped me. I tried several different places and types of resources to get information on this question. This is a discussion that I found that seemed to put it all of the bits and pieces in one place. I hope it will be as useful to others . I would like to hear what others are doing and why. Just as a point of discussion. There lots of ways to accomplish the same goal. Peace Out! Two Methods to a Great Clean: Sanitizing and Sterilizing "... The most common chemical cleaners used as sterilizing agents in horticulture are bleach and hydrogen peroxide. When you are sterilizing with a chemical cleaner it is always a good idea to wear gloves and goggles to protect yourself from potentially abrasive chemicals. Common household bleach usually contains the active ingredient sodium hypochlorite, which is the same chemical compound commonly used in disinfecting waste water at treatment plants. Bleach is a great sterilizer but can leave a residual so equipment needs to be double or triple rinsed. After every harvest, a hydroponic crop grower can create a bleach bath (1:1 water to bleach) to soak the hydroton, air stones, submersible pumps and net pots to ensure they are all sterilized before starting the next crop. After soaking in bleach solution, growers should triple rinse all equipment before using it again to ensure all potentially harmful residues have been removed. Hydrogen peroxide (H2O2) is water with an additional unstable oxygen molecule or an oxidizer. Its composition is truly valuable to the horticulturist because as hydrogen peroxide breaks down and loses its unstable oxygen molecule, it turns into water: H2O. Water is obviously non-toxic to plants and beneficial microorganisms so it is an ideal byproduct of sterilization. I prefer hydrogen peroxide to bleach for the sterilization of nutrient reservoirs, hydroponic systems and all propagation equipment including clone machines. Reservoirs, cloning equipment, and hydroponic systems can be wiped down with a clean rag saturated in 3 per cent hydrogen peroxide. For larger hydroponic systems or systems that are too difficult to wipe down, a diluted 35 per cent hydrogen peroxide (2:1 water to 35 per cent hydrogen peroxide) solution can be run through the system for one hour. Rinse the system with clean water to rinse out any remaining hydrogen peroxide before returning the plants. For sterilizing clone machines, run a 4:1 water to 35 per cent hydrogen peroxide solution for about an hour. As with the hydroponic system, rinse with clean water before returning clones to the machine. Extreme caution must be used with hydrogen peroxide especially when it is in higher concentrations. Growers should always protect skin and eyes from contact with concentrated peroxide.""