400w HPS distance until bleaching effect?

anonymuss

Well-Known Member

• Jan 9, 2011

• #1

what is the closest u can have an HPS to the canopy if heat isn't and issue?

 

dyzel

Well-Known Member

• Jan 9, 2011

• #2

By saying heat is not an issue, I assume you have adequate exhaust and ventilation systems in place.
Generally 12 - 15 inches above the canopy is sufficient.

A good way to make sure the temps are ok is to use your hand.

Place it under the lamp, and see how close you can get to the light without feeling the burn on your hand.
The canopy should be no closer than this.

If it can burn you, your plants are no safer!

 

anonymuss

Well-Known Member

• Jan 9, 2011

• #3

right i gotcha the little hand trick is awesome and the hps is air cooled so the hand can get pretty close for a good amount of time and feel no heat.

just wanna know how many foot candles it puts out vs distance vs what the plants can take

 

teryy

Active Member

• Jan 9, 2011

• #4

i heard 400 watt lights lose lumensat like 24 inches... i could be wrong but its a chart that shows lumens,watts,distance

 

moodster

Well-Known Member

• Jan 9, 2011

• #5

heres a graph i found on another post

 

phyzix

Well-Known Member

• Jan 9, 2011

• #6

6" from a 400 watter I got bleaching.

 

anonymuss

Well-Known Member

• Jan 9, 2011

• #7

1' seems the magic number REP!!!