400W Mh vs 400W HPS - will they cover the same area?

[HaHend]

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?

 

[Gadfly]

There are light guys here that can explain it better but the lumens is not what you're concerned about with the HPS/MH. Lumen is just a measurement of brightness for the human eye if I remember right. Both lights will cover your 3x3 space just fine--I use a 400watt light in my 3x3 tent with great results. I would guess the hood reflector for your light would have a greater impact on how the light is dispersed.

 

[GeorgeFoster]

It's all about the hood size not MH vs HPS....your good to go