hey there Aru, so what they say is you need 65W per sq foot you have 16 ft. sq , times 65 (or 50 if you want the lower bound) that's 1040 , you can fit six gorilla glue in ten gallon pots in a 4x4 so for the grow size you're using divide by 2 (you have three plants right?) that's 520 and you have divide by the number of W you have to see how many of those you need for your grow : 5.2 times the power you have. that's conventional wisdom saying you need at least one cob per plant preferable some for the space between them, preferably some for the space near the boundaries of the grow room which will be slightly darker, naturally. what i think is that the 90ยฐ reflector you get with such cobs is really great for growing, get at least one for each plant point directly above it you'll see you'll be golden. hope this helps my friend ! ๐