They are right.
Impossible to say.
But around 400-500 grams per meter if you do it right with a heavy yielding strain.
But don't count on it .
Give it a shot and adjust from there.
What strain are you growing?
This will make a huge difference.
About an ounce a plant is what I would estimate if I was you.
Jdog7000 Reviewed by Jdog7000 on . how many plants can i put in my space? I have a 4'by8' space with two 1000w hps. I plan on doing soil and need to know how many 2.5 gall pots I could put in the space. P.E.A.C.E Rating: 5