How far away with 750w?

[Chubbs9879]

I'm running 1000w HPS at 75%. How far away should I be? Right now I'm at 16". Should I be closer?

 

[Nartak]

Quick Guide - Distance From MH/HPS Lights To Plants

[TABLE="border: 0, cellpadding: 1, cellspacing: 1, width: 600"]
[TR]
[TD="class: rtecenter"]Grow Light[/TD]
[TD="class: rtecenter"]Closest[/TD]
[TD="class: rtecenter"]~ Sunlight[/TD]
[TD="class: rtecenter"]Furthest[/TD]
[/TR]
[TR]
[TD="class: rtecenter"]150W[/TD]
[TD="class: rtecenter"]8" (20cm)[/TD]
[TD="class: rtecenter"]10" (25cm)[/TD]
[TD="class: rtecenter"]12" (30cm)[/TD]
[/TR]
[TR]
[TD="class: rtecenter"]250W[/TD]
[TD="class: rtecenter"]10" (25cm)[/TD]
[TD="class: rtecenter"]12" (30cm)[/TD]
[TD="class: rtecenter"]14" (35cm)[/TD]
[/TR]
[TR]
[TD="class: rtecenter"]400W[/TD]
[TD="class: rtecenter"]12" (30cm)[/TD]
[TD="class: rtecenter"]14" (35cm)[/TD]
[TD="class: rtecenter"]19" (48cm)[/TD]
[/TR]
[TR]
[TD="class: rtecenter"]600W[/TD]
[TD="class: rtecenter"]14" (35cm)[/TD]
[TD="class: rtecenter"]16" (41cm)[/TD]
[TD="class: rtecenter"]25" (64cm)[/TD]
[/TR]
[TR]
[TD="class: rtecenter"]1000W[/TD]
[TD="class: rtecenter"]16" (41cm)[/TD]
[TD="class: rtecenter"]22" (55cm)[/TD]
[TD="class: rtecenter"]31" (79cm)[/TD]
[/TR]
[/TABLE]

150W - covers 2' x 2' (0.6m x 0.6m) area

250W - covers 2' x 2' (0.6m x 0.6m) area up to 2.5' x 2.5' (0.8m x 0.8m)

400W - covers 3' x 3' (0.9m x 0.9m) area up to 3.5' x 3.5' (1m x 1m)

600W - covers 3.5' x 3.5' (1m x 1m) area up to 4' x 4' (1.2m x 1.2m)

1000W - covers 4' x 4' (1.2m x 1.2m) area up to 5' x 5' (1.5m x 1.5m).

If your plants are not burning you are fine,i would keep it at 18" due to my current experiences of HEAT with my 600w HPS @ 16" !

 

[steve]

Good chart - what about cfls' (500 watters') ? consider " CFL- grow.com" Generaly distance from top of plant is about 2 inches at least but with 500 watters maybe 8-12 inches ? for the "sweet-spot" ?

 

[Nartak]

A good way to check if a CFL is too close to the plant is to use the "hand test." Put your hand where the plant is and leave it there for 30 seconds. If it's too hot for you it's too hot for your plants and the CFL needs to be moved further away! Plants can grow a lot in a day, so make sure to give yourself some "breathing room" so your plants don't grow into the bulbs and burn themselves!

Even if you choose not to train your plants, keeping your CFLs close will dramatically increase your yields compared to keeping them further away!

Source : 
http://www.growweedeasy.com/cfls
http://www.growweedeasy.com/cfl-upgrade-guide

Regularly adjust CFL bulbs so they are within 4" of plants but not burning them.

 

[NebulaHaze]

I keep my 600W 16" away, which is about equal to the intensity of sunlight on a sunny day. So, I imagine what you have now is good The closer you get to the ultimate max of light, the easier it is to light burn your plants, especially if it's hot, you're using new bulbs, no glass in the hood and/or you're not adding CO2!

 

[Nartak]

Hey sorry to hijack this one but it hit me..You think it's possible that one co2 exhale bag i have could actually provide enough co2 to prevent lightburn (since i haven't seen any yet and i have been at 34cm (13.5") !? Funny if it would,i always thought of it as a heavy waste of 35 bucks lol...

 

[NebulaHaze]

CO2 can definitely make a difference in high enough concentrations, but I'm not sure those bags actually produce enough CO2 to make a significant difference. I personally would save my money for something else, but I also don't think it would hurt your plants

 

[Nartak]

Oh i realized it's worth it's money (35bucks for a growing assistant in canna-world? Naaaahhh) so im not rly expecting anything from it!It was just a thought that it might provide "some" safety for a lil while...Thanks again Nebula