Dear Readers, I am running a DWC system with a 315 watt CFL light fixture, and am using an airstone with a pretty powerful air pump to oxygenate the water. I had a water pump going, in this reservoir, to keep the General Hydroponics, three-part, FloraSeries nutrients mixed up, but removed it to get the water temperature lower. I also added an ice bottle to the reservoir to lower the temperature as well. I stuck my finger in the water, and it felt ice cold, but my digital thermometer, with it's probe stuck into the water, is reading 73.9 degrees. I was thinking that my thermometer was programmed incorrectly or something. Is 65 degrees the ideal temperature for the water? And does anyone know if it feels very cold? Thanx!