hps 250 distance?

[alex32]

how far above the plants would a 250w hps need to be?. It is quite a cold area, about 18 degrees celcius which is about 65 degrees farenheit. I have just changed from fluoros and cfls to hps. anyone know?

[MegaOctane12]

I recently got a 250hps instead of a 400w because of the heat but I've found its very little at all + wasn't nearly as bright as I expected. What I notice is yeah the ground underneath gets burnt up very quickly. Put your hand between your plant and the light if it starts to hurt then raise it. Generally about 10 inchs or more.

[alex32]

thanks, i have the bulb at about 13inches above the plants, hope it will work, i love growing indicas, alot more than satavas. Anyone else have any opinions?

[turtle420]

Cool looking bushes man! I like 'em! :)

[LIP]

Dude, i also like growing indica's because i love the body stone... its great!

I'd choose indica over sativa anyday

[alex32]

is the distance i have ok then?

[Zandor]

Keep the bulb 12" to 18" above the plants. The closer the better with out burning the top of the plants. you should have a temperature probe to monitor the temperature of the canopy of the plants under the lights.

Closer is better!

[Garden Knowm]

I saw a 1000 watt HPS 8 inches above a canopy of 12 INDICAS (about 20 inches tall.
The HOOD was cooled with an exhast fan that was PULLING the HEAT AWAY...
But not taking the air it out of the room completely..

The plants were 7 weeks into flowering.... There was not a plant in the bunch that did not have a 28 GRAM(1 ounce) MAIN cola... as big as a childs forearm..

CLOSER is better...

THEY were NOT using CO2

If your mind has thoughts without your awareness.. you are unconcious.

LOVE

[amstron]

when I used a 250, I had a heat shield but my area wasnt amazingly ventilated. I kept it 8 inches away and the plants were fine

[the image reaper]

lay your hand on your plant tops, with the back of your hand facing the light ... judge the heat that way ... :smokin:

[Zandor]

Why guess the temperature and take a chance?

http://boards.cannabis.com/showthread.php?t=40868

That will help you

[notanotherteensmoker]

...try googling "hps mh light distance chart" or similar keywords...I found one once online. has inverse graphs that show the distance from plants and the equivalent sunlight intensity.

As far as temps...is it really 65 degrees under the light. Probably higher. 65 degrees farenheit doesn't sound cold to me. When I used to garden delicate plants other than cannabis, I never worried unless the temperatures got below 50F.