Home | Community | Message Board



Please support our sponsors.

Cannabis, Marijuana, Ganja & Greens >> Cannabis Cultivation

Welcome to the Growery Message Board! You are experiencing a small sample of what the site has to offer. Please login or register to post messages and view our exclusive members-only content. You'll gain access to additional forums, file attachments, board customizations, encrypted private messages, and much more!

Amazon Shop for: Portable Greenhouse

Jump to first unread post. Pages: 1
InvisibleDeadkndys420
 User Gallery

Registered: 08/28/12
Posts: 7,829
Loc: █████
How far should I keep a 400w MH?
    #692302 - 11/06/13 07:56 PM (3 years, 1 month ago)

So I was wondering how far I should keep a 400w MH from small seedlings?

Also when I get some ducting how far can it be from an MH with a air cooled hood?

I should mention this is in a greenhouse and I get good airflow in the area it is at.


Post Extras: Print Post  Remind Me! Notify Moderator
Offlinehamloaf
Biometric Precursor.


Registered: 10/21/13
Posts: 164
Loc: Trinity County, CA Flag
Last seen: 2 years, 2 months
Re: How far should I keep a 400w MH? [Re: Deadkndys420]
    #692311 - 11/06/13 08:58 PM (3 years, 1 month ago)

Small seedlings do not require the same amount of intense light as vegging or flowering plants do, so 3-4 feet is how far you want to hang that 400 watt Metal Halide from your seedlings' canopy so long as the temperature at the plants canopy stays within the acceptable temperature range for marijuana in the seedling phase. 

You're going to want to wait until the plants are in full veg before you go getting the lamp as close as you can to the canopy with out causing heat stress.  Once you get some air cooling you will be able to hang that Metal Halide lamp as close as you can get it to your plants canopy without the lamp causing heat stress to your plants' canopy.  A good general rule of thumb as to how far to hang a 400 watt HID from the canopy of plants is 10-18 inches depending on climate and environment.


Post Extras: Print Post  Remind Me! Notify Moderator
Offlineloki
Registered: 07/31/08
Posts: 8
Last seen: 1 year, 7 months
Re: How far should I keep a 400w MH? [Re: hamloaf]
    #692394 - 11/07/13 03:50 AM (3 years, 1 month ago)

Best to use the back of your hand as a temperature gauge, if the back of your hand feels warm, move the light up a bit, as they grow stronger, warm is fine, hot is never good.


Post Extras: Print Post  Remind Me! Notify Moderator
Jump to top. Pages: 1

Amazon Shop for: Portable Greenhouse

Cannabis, Marijuana, Ganja & Greens >> Cannabis Cultivation

Similar ThreadsPosterViewsRepliesLast post
* horizontal and vertical lamps dmtcorey 1,102 6 12/04/10 12:58 PM
by CrayolaHalls
* getting a 400 watt light (hps or mh) ismokeweed 2,494 13 06/08/13 10:17 AM
by SmokeSomeHash
* room temp and canopy temp dmtcorey 4,044 10 02/07/11 12:10 AM
by dmtcorey
* 400w HPS grow pong 8,716 11 10/23/11 02:20 AM
by growclick
* using MH light for seedlings?
( 1 2 3 all )
pheed 9,769 43 12/03/10 02:06 PM
by maryanne3087
* 400w HPS light Picklez 4,349 15 02/02/10 10:31 PM
by Picklez
* Two Lamp T-5 Setup for 40$
( 1 2 all )
coda 3,840 24 11/07/09 01:58 PM
by coda
* MH pre beginner's question sidetwist 638 8 04/18/12 04:44 PM
by Hawksresurrection

Extra information
You cannot start new topics / You cannot reply to topics
HTML is disabled / BBCode is enabled
Moderator: FurrowedBrow, Magash, Dr. Siekadellyk, phychotron
805 topic views. 2 members, 108 guests and 53 web crawlers are browsing this forum.
[ Toggle Favorite | Print Topic | Stats ]
Search this thread:

Please support our sponsors.

Copyright 1997-2016 Mind Media. Some rights reserved.

Generated in 0.02 seconds spending 0.003 seconds on 14 queries.