MH and HPS lumen comparison

Since a 400watt HPS puts out roughly 50,000 lumens, wouldn't it be better to just use this light instead of in conjunction w/a MH which puts out about 35,000 lumens at the same wattage? Or does the spectrum factor outweigh the lumen one? Im planning on buying an HID system to replace my 240watt cfl setup.

right spectrum for works the best.

mh veg hps for flowering

It's not about lumens it's about PAR Watts and the fact the left side of the visible spectrum contains more energy. Lumens refer to what the human eye detects and the human eye is far more sensitive to green/yellow bands of the spectrum... Going off lumens on HID bulbs misses the point entirely; you're growing a plant, not eyeballs.

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Image taken from Sunmaster grow lights website.