Indoor Need advice for distance to keep HPS @ 500 Watts for sprouts

[Cap'nCrud]

Hello All,
I have grown indoors several times now, but I have never used my HPS for a grow light for new seedlings. I read that the Mephisto boys use HPS for theirs, so I know it's alright to do so, just wondering how far to keep it away from them, don't want to stress the little girls. TIA

 

[Simplicio]

Hello All,
I have grown indoors several times now, but I have never used my HPS for a grow light for new seedlings. I read that the Mephisto boys use HPS for theirs, so I know it's alright to do so, just wondering how far to keep it away from them, don't want to stress the little girls. TIA

Hang the lights too high, and growth will be slowed a little, and without enough breeze, the sprouts might stretch dangerously.
Hang them too close, and it can kill the sprouts.
I usually look at the manufacturer's recommended distance for seedlings, and then increase it a few inches.

 

[blowyourmind]

I've used 600hps a Long time

My distance to seedlings 80cm high
Then I kept it 60cm.

250hps = 25cm/10 inch
400hps = 40cm/16 inch
600hps = 60cm/26 inch
1000hps = 100cm/39 inch