Thanks Zandor. Can you tell me how you do your add backs, cause as I'm understanding I'm stressing the plants by adding back with just plain water. Maybe I should switch to ebb and flow buckets where you have a seperate rez thats always consistent. Right now I have 3 plants in a 12 gallon dwc bin, water is going through a chiller @ 68 degrees, and then going right back in the 12 gallon tub. Pretty much everyday I add back, sometimes with plain water, and sometimes with full strength nutes. I think I need a little more stability.