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Growing ABOVE a light source?

T

Threshold

New member
Hey guys.. So I'm doing a smallish micro grow with cfls and last night I had a thought hit me and wondered if it would work.. As you can see in my pics I have the cfls on a rack and usually have a reflector on top but could I place another screen above it and train a plant above the lights to make use of the full 360 degrees of the bulb? To my knowledge the plant will grow towards the light source so if that source is downwards...

Thoughts? Am I crazy? Cheers [/URL[URL=http://s1183.photobucket.com/user/darktimmy1/media/Mobile%20Uploads/2016-02-07%2009.36.36.jpg.html]
 
exploziv

exploziv

pure dynamite
Administrator
Veteran
In theory it might work. But plants have hormones in them that also follow gravity, so it will sure make for a disoriented plant. But you can try, it can either yeld some results, or will make for an interesting experiment. But I'm almost sure you will have to invest more time into that plant than if you would grow it normally, and results will probably be less than expected compared to a normal grow.

Later.edit: This just hit me. Wouldn't you get more illuminated canopy surface if you would go vertical, with pots all around the bulbs (which would sit in the middle)?
 
Last edited:
Phaeton

Phaeton

Speed of Dark
Veteran
I ran T8 replacement LEDs underneath a row of plants, two LEDs, one tube on each side aimed up. These were 5000K white LEDs. I had heard more light from underneath would help control stretch and I try anything.
After one harvest there was no difference I could find with my naked eye and the yields were within the average for the total watts used. With no positive gain for all the extra work I did not do any more harvests.

The lower leaves I was attempting to influence react to the ratio of Far Red (730 nm) to Deep Red (680 nm). The sun puts out equal amounts of both and more of the Deep Red is absorbed compared to Far Red.
Thick canopies have a lot more Far Red on the lower leaves than Deep Red causing the plant to stretch in an attempt to get above the perceived canopy.
HID bulbs put out 4:1 Deep Red at the bulb and LEDs that even have Far Red use about 9:1. This skews the ratio to the point where adding a supplement underneath to control stretch is difficult to get correct.

But for overall growth, more wattage on the leaf is more wattage on the leaf, bottom or top.
 
P

Plush1

Member
Screw some shelves around the edges on the second level, dangle a single 125w CFL from the roof in the middle of those shelves and circle some plants around it like a donut. Might need a stronger fan to ensure enough air pulls from the bottom.

You've got a whole other space up there!
 
P

Plush1

Member
Phaeton said:
I ran T8 replacement LEDs underneath a row of plants, two LEDs, one tube on each side aimed up. These were 5000K white LEDs. I had heard more light from underneath would help control stretch and I try anything.
After one harvest there was no difference I could find with my naked eye and the yields were within the average for the total watts used. With no positive gain for all the extra work I did not do any more harvests.

The lower leaves I was attempting to influence react to the ratio of Far Red (730 nm) to Deep Red (680 nm). The sun puts out equal amounts of both and more of the Deep Red is absorbed compared to Far Red.
Thick canopies have a lot more Far Red on the lower leaves than Deep Red causing the plant to stretch in an attempt to get above the perceived canopy.
HID bulbs put out 4:1 Deep Red at the bulb and LEDs that even have Far Red use about 9:1. This skews the ratio to the point where adding a supplement underneath to control stretch is difficult to get correct.

But for overall growth, more wattage on the leaf is more wattage on the leaf, bottom or top.
Click to expand...

I agree and I find that plants with the light source at the side or below will simply fill out better wherever the buds are closest to the light and there is no overall drop-off or benefit. I still have to super-crop a sativa once in a while as it attempts to spear thru the roof. They just swell fatter wherever the light is closest. My plants on the top shelf are always bottom heavy.

For the OP, here are some older pics of my perpetual grow showing what I was talking about. One light on the bottom, one on top. The pic with the purple fan has just a 600w HPS in the very middle and look at the buds growing to the roof. Just not as fat as you'd like.

In the next two I had installed a 400w on a stand on the floor and raised up the 600w and the buds get thicker now and I can really pack the room during the summer. 19 BOG SSK's and Dinafem WW's was the record this summer. I stretch the new plants on the back shelf and move them forward when the next batch is ready to introduce. You can really grow a lot with just a couple bulbs.

 
T

Threshold

New member
Thanks for the reply guys! Doesn't seem like I'd gain much from doing it.. Unfortunately where I'm from cfls over 24w don't exist.. Only the standard ones you see there are available without looking at importing some.
 
coldcanna

coldcanna

Active member
Veteran
I haven't ever put lights underneath, but I have layed plants sideways and I can tell you that part works fine. Have you considered putting a mirror above the bulbs? From where I'm sitting it looks like there's enough space above it to add another shelf for 2 more plants and then build another fixture for the top.
 
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