Hi, I read that 3'x3' (9 sq ft) is the ideal size for a 400W HPS bulb (~45-50W/sqft). However a 400W HPS bulb has around 60.000 lumens whereas a 400W MH bulb has around ~35.000-40.000, so roughly 33% less lumens. Therefore I asked myself if the coverage area for a 400W MH woud drop by 33% compared to a 400W HPS bulb? If that would be the case the light coverage would only be ~ 2.5'x2.5' (6.25 sq ft)?e What are your experiences? How much area can your 400W MH cover?