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?

 

[Jnugg]

Either will do in a 3x3 area.

50w per square foot minimum is for flowering although I like to veg with that much too for faster growth.

IMO 50-65w per square foot is ideal for flowering.

You can vegcwith as little as 30w per square foot if needed,but plants will be a bit leggier and grow slower.

 

[vostok]

I'm with Jnugg, most growers who veg with a 400w Mh are vegging younger and small er plants 6-12 inches and so move the 400w Mh closer to get even more lux at risk of increased temps, later with a 400w HPS more lux higher temps and older plants and taller plants raise the light