Howdy SwitchH2O. I run the 'plain' water for three to four days, drain, and then harvest. The results from using the FloraKleen flushing additive made a remarkable difference in the smoke by reducing the harsh 'green' effect and shortening the curing time in the jars. I do not know how, or what they use, but, in my opinion, it is worth the extra time and cost. The bottle says that it can be used, as well, to help remove or reduce excessive buildup of 'salts' in the reservoir(s).