BC Growers Association

Member Profile

• Grower 1

  Grower 1 is an organic grower from British Columbia. He spent 5 years studying university biology and was a member of the biology coop.  This meant that he would go to school for 4 months and then work in the 'field' for four months (called a work term).  Plant physiology, entomology, and plant genetics were specific fields of interest.  Work terms included working for Safers Soap and Applied Bionomics with pest management.  This involved studying predatory bugs and insecticidal soaps.  He also worked for the Ministry of Forests in their breeding program and pest management departments.  He has now working independantly doing his own private research.

   

Cultivation Method

• Grower 1 only grows indoors in soil based mediums.  Fertilization is strictly organic and pest management is biological.  His forte is maximizing his yields per light or watt. This is the opposite of the main thinking where the grower is trying to maximize their yield per square foot or per clone. His reasoning is that for most growers, lighting or more specifically electrical consumption, is the limiting resource. Growing room (square feet) is usually a surplus resource. Limiting resources are usually electricity, number of plants (legal considerations), and other times space. Often the very nature of a hydro garden is that it's limiting resource is space or square feet. I will concentrate on the aspect of assuming electrical consumption is the limiting resource and the grower's goal is to maximize their yields with respect to each light.

• There are many factors to consider when attempting to maximize your yield per light. Lighting intensity, number of lights, reflective hoods, light spectrum, light movement, plant size, plant genetics, and cultivation methods all play an important role. Each factor has to be such that it compliments the other as the plant can only produce as much as the weakest link will allow. If the weakest link is the light intensity or watts/ft, then we should be getting the most out of the lights. In the paragraphs to follow, I will discuss each of the parameters. The figures I will use are easily debatable so try not to take them too literally. They are just to try and illustrate the points being made.

• A plant can only absorb and process so many lumens at any point in time. The excess are just wasted or spilled over. For instance, if you blast 100 watts/ft at a single square foot, the plant tissue in that square foot will become overloaded and there will be a maximum amout that that area could yield. The plant's metabolic pathways will just max out. However, if you split that 100 watts between two square feet (50 watts/ft), each square foot would be able to use the light more efficiently. The metabolic pathways will better be able to process the light and keep up with utilizing the light absorbed. The square foot receiving 100watts/ft may outyield the square foot receiving 50 watts per foot, however, the two combined 50watts/ft areas will easily out yield the 100 watts/ft area. Therefore, to within reason, plant tissues use light more efficiently at lower light intensities. However, as the light intensities drop, so does the overall flower quality. So there is a compromise to be made here between maximizing yields and maintaining quality levels.

• (to be filled in - Discuss genetic relationships and lighting requirements)

• I guess the first thing to consider is the useable area of each light. Most conventional thinking is that a single 1000watt HID can effectively light a 4 by 4 garden or 16 sq ft. This works out to 62 watts per foot. Light falls on more than a 4 by 4 area, but generally speaking, the outside or peripheral light is usually considered too weak to adaquately support plant growth. However, if you place two lights side by side there will be an overlap of lumens between each light. Where the two peripheral areas overlap, enough lumens then hit to adaquately support plant growth. Therefore two lights could effectively light say a 4 by 10 area or 20 sq ft per light. This alone increases the efficiency of each light by 25%. Make it three lights in a row and now the effective area can climb to 4 by 16 or 64 sq ft. The two outside lights will effectively cover a 4 by 5 area. However, since it will be overlapped on two sides, the useable area under the center light can be increased to a 4 by 6 area. This amounts to an overall 33% increase in effective coverage for each light. Now make it 4 lights in a square pattern and we really turn a corner by being able to light a 10 by 10 area. Each light will have an overlapping area on two adjacent sides and therfore each light can effectively light a 5 by 5 area or 25 sq ft. This works out to be 40 watts per sq ft. This means that by using 4 lights together, the efficiency of each light can be increased by 56%. And we haven't even started moving them yet ;-) Just for the record, in comparison, 4 lights in a row would only effectively cover a 4' by 22' or 88 sq ft area. This works out to be 45 watts per sq ft.

• Moving the lights increases production on several fronts. First is that it spreads the light over a larger area. One of the problems with stationary lights is that leaves move to face the light. By doing this, the upper leaves block light from reaching lower portions of the plants and therefore limiting production to the upper 6-8" of the plant. However, by moving the lights, the leaves are never able to fully block the light from penetrating into the plant canopy and therefore production can be increased to between 12" and 24" depending on growing style and cultivar.

• The topic of light penetration brings up another important concept to consider, depth of productive canopy. The garden isn't just a 2 dimensional entity, it has depth. The deeper into the canopy you can get production, the more efficient your garden becomes, the more that is yielded per sq foot. Therefore we are trying to maximize both the number of square feet lit by each light AND the production of each square foot. I'm going in circles here so I'll leave it at that, haha.

• Back to moving the lights. There are two basic methods of moving your lights, linear or circular. I've grown plenty with both setups and have found the circular light mover to be far more efficient than the linear ones. I think my intial argument showing how 4 lights in a square formation are more efficient than 4 lights in a row explains the most basic advantage of the circle. However, it even goes much deeper than this.

• Another advantage of the circular light mover is that you can combine light spectrums. Both HPS and MH lights are good for supporting flower developement and plant growth, but each is lacking to some degree. Each is lacking in seperate areas of the light spectrum with the MH being better for plant health and the HPS being better for flower production. Therefore, by combining the two spectrums, we get a more complete light spectrum and the plants are able to use the light more efficiently. They can then, therefore, get the same job done with less light intensity. In my experience, I have found the best ratio of HPS to MH to be 2:1. This works perfectly with the 3 arm suncircle. It's hard to get an even spectrum mix with a linear light mover.

• Another advantage of the suncircle (especially the newer ones with the faster motors) is that the lights can be much closer to the plants.

• More to add?? I dunno yet

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