White spots on the leaves.

somthing suckling on your plant, probably. "pyrethrins" are an option. that'll kill on contact. they also breakdown quickly. need to know what it is and attack it at multiple stages of life cycle, if possible. Better to deal with it in vegetative phase... you have more options that won't impact the end poduct. if it has a larva stage, get some bti, that'll prevent new larva from pogressing once up and running. BTi is a great prevenatitive measure. it is microbial, so some methods of growing may not work well with it. e.g. you don't want an h2o2 drench or some other sanitizaing agent killing off the culture etc. what you have may not have a larva stage if an arachnid, but putting down some 'mosquito bits' or using a mosquito dunk in you water can will avoid a whole bunch of problems. never fret about gnats again.