Ideally, for one square meter grow box I wouldn't go below 400 watts of light. So actually you should be adding more of those 150W HPS bulbs, let alone T5's.
Hi. Even feeding with every watering is fine, as long as you keep the nutrient concentration at optimal levels. Meaning: the frequency of feeding doesn't burn the plants, but the concentration of nutrients does. For example, let's say you were feeding once in two days, with 2ML of nutrients per...
wow! Very nicely drawn...
If possible, separate the lights area form the grow area (where the plants are), this way you will have far less problems with heat, but you will be needing two fans, one to cool the lights and the other one to move the air from the grow area. You won't be needing the...
Actually I would always go with the out take fan only (connected to a carbon filter of course). No in takes. Ideally I would place the fan at the bottom of a grow room and poke many samller intake holes near the top of each grow room wall. This way you don't need an intake fan while air...
How exactly big is your loft ? If it's only slightly bigger than your tent, then you're going to have to find a way to vent out that heat. There's no way plants could survive in that environment.