help needed

any1 know what makes weed grow extremely slow even when the atmosphere is fine, temps, humid, lumens, all ok growing 4 brainstorm in a 4ft x 4ft tent. no intake fan or out take as windows are kept open 24/7. just a desk fan on the outside to push fresh air in, i am ready to quit after all this wasted money and time but would still like to know what the cause is.. many thanks..

Soil used? Nutrients and how you've used them but most importantly, lights? Types and distance from the plants? And plants need air blowing across them, even if the air and temps are perfect.

thanks for the reply, another user says phosphorus difficiency, hps 600w and mh 250w, as close as i can have them and there is an isolating fan in the room aswell, using a mix of perlite seed and cutting hydroten balls and sand for good drainage. not using nutes yet because their not showing that they need it. whats your personal opinion lad..

If you put a new seedling directly into a large pot you will see little or no growth
as the plant is genetically programmed to grow roots before foliage. Don't make sense
to grow a large canopy without a root system to support the plant.

BigSteve.

they were transplanted from 1/4 litre pots after seeing very little growth after a month, so it cant be that.. but thanks anyway