at first i need to say, very nice plants up to now! keep on going!
@TheMongol i read the whole thread. For your light question i maybe got an answer. The plants arent that tall atm but got big leafes. He also said that the P150 isnt the only light he is using so there is more PAR than the 350.
Next thing is if he stretches the plans for getting more width he can cover more surface where the 350 PAR hit. So at the end you got about 3 plants on the same space where he has 2. Thats why you go on more PAR for less space to equal his more space with less PAR. But in a way you are right because if you double the distance the "hitting" PAR gets divided by 4. Formula is ( I2 = I1 * (r1/r2)² ) [ I1 = intensity on distance r1 | I2 = intensity on distance r2] the only thing needed is a value on a certain distance and u can calculate for yourself.
cheers