Your plant doesn't look bad enough to be cutting anything off. Besides, even if a leaf is damaged, the plant can still take nutrients from it. I always let my damaged leaves get consumed and don't take them off until they are dry and yellow/brown. Do you know your humidity level? If your RH is too low, you might have to water more often. My RH is at 20-30% and I go through a half a gallon of water per day in DWC.