Hey splat u said the plants are 3 weeks old ?....If so they look a little undeveloped for that time frame?hmmm...I would think maybe u should switch to a light period of 24-7 for another week or so....just to get them a little more developed...or 20-4....have u used any superthrive with ur waterings i used it and it works very well for the transplanting and for vegging....its not a nute its an additive and contains vitamins and hormones for building healthy roots and increasing foliage....u should definately get a ph kit and test that tap waters ph.....just my 2 cents:thumbsup: