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!
|
 Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
|
 Deadkndys420
Registered: 08/28/12
Posts: 8,689
Loc: █████
|
 How far should I keep a 400w MH? 
#692302 - 11/06/13 05:56 PM (10 years, 5 months 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.
|
 hamloaf
Biometric Precursor.
Registered: 10/21/13
Posts: 179
Loc: Back in the USSR. 
Last seen: 4 years, 9 months
|
Re: How far should I keep a 400w MH? [Re: Deadkndys420]
#692311 - 11/06/13 06:58 PM (10 years, 5 months 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.
|
loki
Registered: 07/31/08
Posts: 8
Last seen: 8 years, 11 months
|
Re: How far should I keep a 400w MH? [Re: hamloaf]
#692394 - 11/07/13 01:50 AM (10 years, 5 months 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.
| |
|
|
|
Threaded
Previous
Index
Next
Edit 
Reply 
CLEAN AND EASY STB TEK
HOW I GROW MY SHROOMS
