so i got this cool new toy. i'm sure you all have one but i don't hear it mentioned very often. it's my new light meter. it measures foot candles which can then be converted into lumens. just hold it next to the plant and read the needle. i learned a lot in 5 mins. you can read all you want about light depletion over distance but with this you actually see it. it's rather interesting how much difference 1" can make. i paid $30 for it at my hydro store.