How many plants under a 1000W(HPS) to maximize the yield?

[The_Chronicler]

I was thinking about

16 plants (How tall should they be before the swich to 12/12)
OR
25 plants (How tall should they be before the swich to 12/12)

That many plants in that amount of space is pretty much a SOG. Try then with 3 plants and tie them down, if you dont want the SOG.