I made this for the cause:
Your HPS is a great lumen & heat generator.
HPS.... PAR light? Not really. *Ideal* light? No, again.
Lumen measures intensity to human eyes! Yes, they have that. Spikes beyond 760nm(IR radiation, aka heat waves) yes, those too! Ideal 420nm-460nm & 640nm-680nm spikes? Nope.
Plants 'see best' indigo/blue/cyan and orange-red light. HPS is green-yellow and yellow-orange. What we see best, and plants see best are basically inverted on the visible light spectrum. Human vision is basically a tall bell-curve peaking at ~560nm. This coincides with the peak or near peak(s) of most HPS bulbs. That's why they rate so high in lumens. Right smack DAB in the middle where plants maybe absorb around 50% of that light, but are only using 20-40%(with ~20% going right through the leaves, and 10% reflection). Instead of 80-90% like 400-500nm and 620-680nm.