they are .. I have a 6 tube fixture (27,900 Lumens) I veg under ..
I reccon I would go that way if it was me .. less power .. more safe .. I just like em .. but you realy need to keep em low .. better do realy low Autos then one big auto then ..
I found out 2-4 inch`s away from the tops and the plants seems to do best ..
my sun analyzer/meter give me a nice 1,5K foot candels (+16K Lumens) up ther ..
but a foot away I can even get a reading .. after 10 inch`s I dont reccon they will do much for bud production .. so need to keep the plants low and close ..
p.s.
my 600W HPS give me 3-7K foot candles (32-75K Lumens) 16-25 inch`s away ..