Well I don't see anything WRONG with any of them... one's deformed, that might pose a problem for you later on, but otherwise they're just slow growers. A few things could be causing this.. how often is the air in your growroom replaced? Where is your air coming from? Hopefully not from inside... stale air can really stunt a plant, so if you dont have a co2 system, you should try to configure a way to pull in fresh air and have it vented out of the growroom.. You can manage this with as little as a few dryer tubes a fan and a garbage bag.. Just have the "intake" end of the tube and stick it out a window and cover up the open area with a sheet of cardboard or something.. This is SUPER important. Below pic 1 is my first attempt at (2) weeks... pretty sad I had no true ventilation, simply a mess of fans blowing every which way. Pic 2 is my second attemp at 2 weeks, and as you can see, FRESH air makes a hell of a difference. And if already HAVE fresh air coming in, then I'd have to say It's your soil. It looks like it has a high bark content, and not much perlite, Making this another possiblity of the slow growing. Ya see the all that bark forces the roots to go under more stress then they should have to, and on they're way to the bottom of the pot they have to work around all that bark and can sometimes get entangled. Not only that, but if you have a ton of bark in your soil that's less actual volume in the pot for your roots to thrive in. Get back to me on those two issues and if we can't figure this thing out on our own we'll call in the big boys... Zandor? latewood! Garden Knowm... Hardonn?

Peace