Nothern Lights Auto - Seedsman

It's coming along now... Few days ago the pistils on the plant seemed to be little bit brown, changed the nutes with a fresh mix and it's seemed to have perked up again. Been defoliating a bit, but unsure if I should go all the way and remove most of the fan leaves? Some do, but from what I heard you leave as many fan leaves as practical, and to only defoliate fan leaves blocking bud sites, or the ones allowing poor air circulation to the plant, ie overcrowding. Anyways, my main concern is how much darker this plant is to the rest of the plants. Can anyone shed some light into this? Update - a big shout out to all the growers who answered my grow question. Took all your advice into consideration... Just changed the Res, cut the excess nitrogen and just fed mostly PK elements with added Cal Mag. Also the air lines were twisted from the pump and could not pump enough air into the bucket. Might have been like that for at least 12-24 hrs... Feel like since acting on those changes this morning it's already made a difference. Will update soon.