Lets get THE TWO LAWS OF DWC! clear (as in how we like our water)
LAW 1: RES TEMPS MUST BE UNDER 69.8 DEG Fahrenheit!
LAW 2: YOUR RES MUST HAVE COMPLETE DARKNESS!
If you can hold your empty res up to the grow light wave you hand between the res and the light, look thru the inside of the res...