Help please nitrogen def or not enought space???

Hi i have about 16 plants in 3 or 5gal pots in a 3.5x7 shed i have 3 400w hps lights, a 8000btu ac, a regular fan for intake, and 2 other fans for circulation and a c02 supplement. up until the 2nd week of flowering my girls started getting these brown spots that consume all the bigg fan leaves and most of the top fan leaves now (4th week) i have not really given them alot of nitrogen(or alot of ferts period)(reason for not putting alot i wanna make the smoke alot smoother and i have notice that with just watering the buds dont come out all that big but they are extremely good smokes(onnly tried just watering with smaller plants 12-18 in when finished i wanted to try just watering bigger plants to get more but the just watering dosent seem to work with big ones)) THe ferts i have are (veg) fish emlulsion 5-1-1, (Flower) pure blend bloom, bat guano 0.5-12-2, potassiam 0-0-5, superthrive (also in veg). I feed like every 3 days and water almost every day. I put the rec dosage. i just want to know if its a nitrogen def or is my room to small and they are not gettin enough light penetation into the inside of them thats causing this any input will be greatly appreciated thanks

Welcome to RIU

I'm not even stoned and i'm having a hard time following you. Just use a bloom nute and be done with it....get an organic one.

all my nutes are organic nothing chem here and yea sorry i just get caught up when i start typing i rather talk

Are there any pics up sorry im new at this