Bro I am sort of in the same boat. But yours is off the hook stunted. Check out my thread I just started "Whats up with this Plant" That one is like 20 days. Doesnt sound like you are over watering. Different strains grow different. I think I am experiencing that. My first hydro grow was with some freebies NLX and they took off like a bolt and never looked back. The grow was worry free but this one is making me wonder "WTF" All you can really do is try things like you said backing off the water a bit and see what happens. This is a science and practice is the key I have learned. Yeah we all want the dank dookie buds our 1st and 2nd grows but sometimes it just doesnt turn out that way. School of hard knocks! I will keep an eye on your thread as ours are somewhat similiar!

Peace