So i just completed my first grow with 14 plants in a 7ft x 3ft area with 600 watts hps lights and reflective pannels. NExt grow i want bigger buds and i was thinking of increasing the light to do so. SO to figure out how much light these plans should get ideally i want to know how much light i should i be using per square foot. Does anyone know? and how do the reflective plannels come into play?
Figure 100 watts of light for the first plant then an additional 50 watts of light for each additional plant. Also consider the more light each plant gets the better. So an 800 watt set up would put you a little over the minimum amount of watts of light per plant or a 1000 watt would be a nice increase in watts of light per plant but 2 600 watt light set ups would be better because the 600 watt ballasts are more effiecient for the amount of lumens put out per watt of electricity used. Another thing to consider is a light mover.
if i were to measure the square footing would i measure the whole room, or just the part that below the light?
This is true for HID lighting. It is not the case, however when using low-wattage CFLs or fluoro tubes. Measure the areas you want to cover, which is to say your plants. If you don't fill the whole room you don't need to measure the whole room, though you probably want to make some sort of divider (plywood, cardboard) to pen in the space you are using.