I know this is old, but I cant believe the info people are giving at this forum, do the ******* math.
1000w HPS - 145,000 Lumens
600w HPS - 92,000 Lumens
400w HPS - 58,000 Lumens
600w HPS + 400w = 150,000 Lumens
More Lumens with a 600 and 400, this is because 600w HPS is the MOST...