This doesn't sound too late to me, from your description.
The old adage is when you think they're ready, wait another week. It's not unusual for new growers to err on the side of harvesting a little too hearly
Remember most of the weight is packed on during the last few weeks
Best wishes for you
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Thanks for the update sfhaze. Been following your progress with interest. If you're happy with your current yields and the quality, that's great! Sounds like it's meeting your needs.
If you want to improve them even more, here are a few things you might want to look at when you're ready to expand:
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By the way, is this the cabinet you're using? Black&Decker SpaceRite Series XL Utility Cabinet
If so, you're in a 17.7" x 34.6" x 71" (lwh) space. With the doors closed you've got perhaps 16" x 33" of usable area per shelf - i.e. 16 x 33 /144 = 3.67 sq. ft. Call it 3.5 sf or so, or ~7 sq. ft total, for both the top and bottom areas.
Preface: With HPS, my expectations on yield for production gardening are about 2 oz for every square foot of garden area per harvest. So that's roughly 6-7 oz for 150W HPS (3ft+), and 16 oz (1lb) for a 400W fixture (8-9ft area). That is the benchmark I will be using for determining 'equivalency' with any LEDs entering the market. Another way to look at it is a yield of roughly 1.1g per watt, with HPS.
So with your space, I would expect ~12-14 oz per harvest using HPS.
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The specs on the Haight Solid State PPF-400 units are interesting:
-6 watt LEDs
-90W total
-140 degree lens viewing angle
Your average HID and reflector cover 120 degrees downward from the light, so this is an even wider distribution than with HPS. Even with high output 6W LEDs, the light intensity falls off very quickly away from the lamp, using the inverse square law for emitted radiation. On average, this means that:
If you use 1 ft from the light (point source) as your baseline reading:
- At 2 ft, intensity = 1/(r^2), or 0.25 (75% reduction in light intensity)
- At 3 ft, 1/(3*3) = 0.11 (89% reduction)
- At 4 ft, 1/(4*4) = 0.0625 (94% reduction)
Beyond that, the light available for growth/flowering is negligible.
So every time you double your distance, relative intensity is 1/4 of what it was originally. Unless you're using a coherent light beam (e.g. a laser), all light follows this immutable law of physics (and, even narrow lasers fired from the earth to the moon end up ~3-4 ft across when they reach their destination, so lasers aren't totally immune, they just exhibit much less dispersion over short distances).
LEDs are nice because they can be directed (so you're not losing intensity due to reflection and dispersal using an arc lighting radial emission source such as HPS), but the lenses used in distributing the light (so you have consistent coverage) scatter this light widely - and LEDs will never make up for the intensity of an HID, color spectrum/efficiency notwithstanding.
That's why LEDs of all lights are best when used very close to your plants - similar to fluorescents. With short plants, even canopies, and close proximity to the light, you will have the best results. That means ScrOG or SOG, which I believe is what HSS designed these for specifically - production growing. If so, then they definitely knew what they were doing.
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(On a side note: I think the general marketing used by most companies in promoting LEDs is doing the average consumer a great disservice. One must think of LED in a whole new way, and a different paradigm from, HID lighting. We know why companies do it, of course: 1) People like to categorize things, and saying that 'A=B' makes the decision making process easier - even if that's not entirely true. It also keeps people from having to think too hard...; 2) LEDs are expensive right now, so marketing a low wattage LED unit as equivalent to a higher wattage HPS makes the initial financial hit seem less offensive, even with the cost savings over time; 3) The majority of folks considering LED will be switching from HIDs, and many manufacturers are trying to market them as a direct (1-1) replacement; and 4) It's marketing, folks - expect some hype!)
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Many new and/or hobby growers are used to growing bushes or small trees with HPS. This growing pattern just doesn't work well with most LEDs (the closest I've seen so far is with the HGL units, which have narrow 30/60 degree lenses to concentrate the light directly under the unit. The downside of that is having a smaller ancillary coverage area - requiring more units to provide effective lighting for larger gardens. Distance vs. intensity and coverage area is a trade-off with all lighting sources. You can't have both - without investing in additional lighting.)
So while we've seen that HSS can grow bushes with their lights, the 140 degree scattering of light means that it's not going to be optimal in those gardens, even with 6W LEDs.
Sfhaze, your plants start flowering on the lower shelf, and finish up on the higher one (or at least, the stretchers do), correct? So if your tallest are 30", from the top of the light to the base of the plant is 3ft. That means the lowest branches won't get very much light at all, even if there was no foliage above to block the light.
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So, here are my suggestions, in order of how much you're willing to change your garden in order to improve yield:
1) Get larger (or at least, deeper) pots. MJ likes to have a long tap root, sometimes half as deep as the plant is tall, depending on strain. The 5" pots you are using will stunt their growth to a certain extent. The plant roots will still spread laterally, but it's not the same for the plant as having room to grow downwards. (How root bound have they been after finishing up?) The need for deeper pots can be minimized - and eliminated by going to a hydroponic system.
2) Flower the plants shorter. If you're going to grow bushes with the HSS, try to keep them no taller than 18", do some LST, and/or top the plants at least once to split the colas (depends on strain also). If at all possible, keep all strains about the same height from the light once trained for more consistent light distribution. For now, you can put the shorter ones up on books or something else underneath the pots to keep all plants as close to the light as possible; should help to reduce the stretching I'm seeing also.
3) Go hydroponic. Even a simple bubbler system with decent air stones can improve your growth rates and yields dramatically, and can be accomplished in a low footprint.
4) Consider ScrOG. You've seen what Mmmmick is doing with his UFO LED grow? Imagine that on two shelves, with a better lighting spectrum and high output LEDs. ScrOG is optimal for your light, and allows you good yields while allowing growers to stay within the county guidelines for medical marijuana growing (6 mature plants or 12 immature and 8 oz. stockpiled, in most areas).
5) Go modular. This allows you to try several different strains and still do perpetual harvesting, if that's what you want.
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Back when I was involved with larger gardens, we used to do custom scrog units with self-contained hydro setups. These had a 2' x 2' (4ft square) base, small casters for easy movement, and grew one plant each up to the attached screen (~12" tall) before being trained laterally. Top them once in veg (or not - again, can depend on the strain), then just wheel them to the flowering area when they are ready.
All plants flower at the same height, you can do different strains (helps to know the stretch for your particular strain in order to maximize filling your screens!), just move them down the row as they progress and harvest when ready. Easy as can be.
(Now, training is a bit more work than just growing a bush, but not a whole lot. But during the stretch and when training, it helps to be there every day to make adjustments. Plants can grow 40-70% of their current height during this period (and with some strains, they will double). Once they're set and in flowering, you can just let them grow, and step away for a few days if you have to.)
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The best LEDs I've seen so far can do around twice the yield vs. HPS on a per watt basis, and I believe that to be a better measurement when comparing lighting types. I think that can definitely be improved on over time as we learn to use these units more efficiently.
With your unit in that space, that would mean we're looking at around:
90W x.2.2g/watt = 198g/28.4 = 6.97 oz, for each unit. In other words, about 2 oz/sq. ft.
So, right around 14oz, with high producing strains and the right methods.
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So I'd probably let them grow to 12" and scrog them individually in bubblers if you want a simple way to maximize yield and still have variety.
One good way to do that with off the shelf components is with the closet storage systems. You could probably fit in two per shelf (4 strains/grow) with some of the smaller ones; take a look at these for ideas:
The Container Store ELFA System
OrganizeIt Basket Systems
(OrganizeIt Components
Shallow Wire Basket
Four Runner Frame
You can probably find a good knock-off cheaper than some of these, just look around to find ones in your size and price range. The 17" tall ones are perfect for a 5-6" bubbler reservoir and 10-12" tall plants. Get a runner system and the shallowest wire basket, cut out every other + intersection so you have ~2" squares, and fix the screens to the runners with twist ties so they don't move around. (Or just wire and tie them to the runner sides crosswise manually and ditch the basket).
Fix the base to plywood and attach low casters. (Or if still using soil, just place them above when ready to train). Drain the bubbler between veg/flower rooms when changing nutrients to put them on the shelves, then refill. (Tip: double up your top shelf if possible if you need to support more weight. One gallon of water in a reservoir weighs 8 lbs!)
You never have to move the plants once flowering, everyone's at the same height, LEDs are 3-6" from your canopy at all times, and the redirecting of plant hormones (e.g. auxins and cytokinins) resulting from lateral training means a whole field of colas to harvest. A little smaller, but loads more of 'em.
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With a wider space, I'm sure you can probably add a couple more ounces to that per light - assuming the manufacturer's 'coverage area' isn't too far off, of course.
Hmmm, a little longer message than I started with, but hopefully helpful to some folks.
Anyway - congratulations on your latest harvest and good luck on your grow, sfhaze. Your efforts and testing with LEDs helps the entire community. We thank you!
Best Regards,
-TL
Amen WheelO. I would like to see more apples and apples comparisons and I don't think grams per watt is as useful as grams/watt*hour for the exact reason you mentioned. I am doing my second grow right now and I know I won't have the same per plant yield because I vegged for half the time I did before.
