How high above the plants is ideal, max, and min? For instance, what is the ideal height to keep your 1000 W MH from the tops of the plant to the bottom of the bulb with a light that is NOT air cooled? Thanks in advance! ps is there a chart somewhere that I missed that explains all this?
Correct height of lights?
- Thread starter Red Fang
- Start date
Hydrolized
Member
Not air cooled is usually the "hand test"...stick your hand under the bulb and see how close you can get it without it getting uncomfortably hot from the radiant heat after a minute or two...There are some charts out there. Something you have to think about is the Inverse Square law of lighting intensity which is why I always air cool....if your getting 100,000 Lumens at 1 foot, you only get 25,000 at 2 feet, and only 6250 lumens at 4 feet...double the distance cut your lumens by 4. This is why I don't understand the people that take out the glass because they lose 10% of light (which isn't true anyways), but now that they can't air cool they have to have the light 6-12" higher than before, losing way more than 10%.
100% Dundee
Member
This one is for the MH since thats what you asked about, google "HPS lumen chart" to get the same thing for HPS bulbs if you need that as well.
D
DJXXPLATINUM
I WOULD SAY AT LEAST 18 INCHES....THE HAND TEST...FOSHO..DJ
100% Dundee
Member
No height is the "correct" height, you want the bulb as close as possible. If you can only get it to 18" thats great, if you can get it closer without any negative affects then you want to do that. All depends on how your specific room/environment/reflectors are setup and what they allow.
it also depends on the position of the bulb, I run vertical bulbs with parabolic hoods and i get my bulbs to within a few inches of the tops.
yeah man, with the parabolic and a vert bulb its within inches...this will only give you better coverage and deeper penetration...
Mine is around 6" to 8" for my 600's but have had 1k's at around 2ft just because I think if it is too close it messes with the trich production. Am I just assuming that or does a light being too close affect trichs.
budleydoright
Member
I get best results 24" on my 600's and about 30-36" on 1 k's
Hydrolized
Member
I haven't noticed bulb distance affect trichs, my 1K's are usually 18", sometimes 12" away before I get light bleaching, and even when they bleach out, the trichs are still about the same. This is with Lemon Skunk.
budleydoright
Member
I get better formed buds when they are at the correct distance, the pistals are longer. My plants right under the lamp have much shorter hairs. This may have something to do with my water cooled lamps.
SacredBreh
Member
RedFang..... lots more than distance to light although very important
RedFang..... lots more than distance to light although very important
Here is a site that is not funded by any companies that has excellent info you are looking for. Much of it is in tables that I cannot copy over here or I would, there are calculators to that are useful, like watts per square foot, minimal distance to canopy for all kinds of lights, Foot Candle to PAR conv erter and lots of other useful stuff. Here is the site:
http://www.angelfire.com/cantina/fourtwenty/yor/lightres.htm
Here are some useful illistrations from the site I could bring over:
Distance to the light is extremely important but the "foot print" of the light and how it is used is just as important. Like I said it has multiple table for distance and PAR for all the distances and min and max watts/PAR/Foot Candles for the different lights also.
Hope you like it. It helped me understand a little more a long time ago.
Peace
RedFang..... lots more than distance to light although very important
Here is a site that is not funded by any companies that has excellent info you are looking for. Much of it is in tables that I cannot copy over here or I would, there are calculators to that are useful, like watts per square foot, minimal distance to canopy for all kinds of lights, Foot Candle to PAR conv erter and lots of other useful stuff. Here is the site:
http://www.angelfire.com/cantina/fourtwenty/yor/lightres.htm
Here are some useful illistrations from the site I could bring over:
Hope you like it. It helped me understand a little more a long time ago.
Peace
No light burns here!
The tent is 5' front to back, and 10' left to right. Its not possible for the bulbs to be further than 30" from the walls.
In some cases the plants are ~10-12" from the bulbs or their tube.
Fuck horizontal gardening. Hoods used in horizontal gardening are actually huge metal radiators of heat. Heat buildup is minimal with a vertically air cooled tube.
The tent is 5' front to back, and 10' left to right. Its not possible for the bulbs to be further than 30" from the walls.
In some cases the plants are ~10-12" from the bulbs or their tube.
Fuck horizontal gardening. Hoods used in horizontal gardening are actually huge metal radiators of heat. Heat buildup is minimal with a vertically air cooled tube.
100% Dundee
Member
I love people who use this as an example as to why NOT to use horizontal reflectors...as if their mind cannot fathom the idea that this might be the reason some of us ARE using horizontal reflectors.
You do know the function of a radiator correct? Aircooled/Ducted Horizontal hoods are very, very effective at retaining and removing the heat(much like a radiator) from a grow space. Sure my hood might get hot, but two inches below the glass is perfectly fine. This is my goal.
Don't get me wrong, I love vertical growing and I can definetely see the appeal of it. But to discount horizontal growing/hoods because they arent what you use or because the hoods actually do what they are designed to do seems a bit silly to me.
