Discussion in 'Grow Room Design & Setup' started by cool2burn, Jan 5, 2017.
Big difference in sounding like a dick and being a dick.
I am working with a number of Caregiver/growers in Michigan.
All have had HPS CO2 grows with 72 plant max (36+- in bud) for 3+ years.
With HPS they are getting 1.2-1.6 lbs per plant.
20 tons+- of AC to cool the grows. What really bugs the Michigan MMMA growers
is that in the middle of winter with sub-freezing temps outside, the AC is still running.
For CO2/infestation/pollination/odor reasons they don't want to exchange air with outdoors.
I got involved mainly over the electric bills in the $3,500-$5,500 range.
The cost of changing over the grows to LED with an installed HPS infrastructure
in place is questionable.
They are doing it because:
Last year Michigan legislature passed bills permitting licensed grows of
500, 1000 and 1500 plants starting in about a year. HB 4827, HB 4209
They are committed to getting these licenses and building out new facilities.
And looking at massive $ no matter which way they go.
The numbers for the LED grow are looking pretty good in this scenario due to the
fact that AC and electric infrastructure are both reduced, and no light movers/installation
needed, no hood ventilation/installation, needed.
Then the savings from all this get applied to the light budget.
What we have learned:
This is mainly about BUD room - haven't addressed veg yet.
1. To take advantage of CO2 they need 1100-1300 PPFD at canopy.
With this, they are getting just about the same harvest per plant as HPS.
We have found that with the 150-160 lumen/watt LED fixtures we are using,
that equates to 50+- watts per square foot.
2a. GrowerA -
With this intensity of full spectrum (white) LEDs, they are getting almost identical
Yields (+-2%) with side by side rows of 4 plants testing in the HPS grows. DWC, same room temps 75f+-, same nutes,
Reflective Mylar around the LED row to minimize light mixing. The LED row "looked" healthier and "looked"
like it would yield more, in the end, it came in lower.
4 plants - 3 Whitefire + 1 Dutch Orange each row.
LED=2419 grams, 4 plants HPS=2449 grams. LED about 1% less.
They gave their "patients" blind choice, (bud density, look, smell and taste) 5 of the 6 patients
had no preference - both awesome. One had a slight leaning towards the LED - likely attributable
to that particular pile.
My problem with this side by side mainly has to do with the fact that they didn't warm up the room at all
for the test. 75% is on the cool side for HPS/CO2 (should be closer to 85-90) and you are "suppose to" run LED
grows 5-7f warmer (90-95f+-) due to the lack of radiant heat baking the plants.
Which means the LED row was 20f too cold.
They are now doing a side by side at 80 degrees. Since the LED row is in the middle of the HPS grow
they are paranoid about burning the HPS plants if they go any warmer. At this temp they "should" see better yields on
both HPS & LED. I wonder at 75f if they are getting any benefit from CO2 (HPS or LED). They know what works and
don't want to jeopardize the rest of the grow.
So thermal handicap considered, the tests were very successful.
Grew HPS for years and got rid of/transferred grow to someone else due to moving hours away.
His new location had limited power and the utility won't upgrade him to 480 amp service which he used previously.
Doing the math for a 36veg/36bud grow with 36 1000w HPS in bud + veg lights + 20 tons AC + other loads
he knew he had a problem. Slowly building out (as he gets additional patents - 12 plants per patient) with blurple LEDs he was quite disappointed.
The plants seemed to do real well for the first 2-3 weeks in bud then not so well. I loaned him 3 fixtures for 10 weeks
and he bought them rather than return them. A couple months later 6 more. Getting much better yields than the blurples
- but that almost isn't worth mentioning. Getting slightly more per plant than GrowerA
3. An optimized LED/CO2 grow at 95f will be a challenge for Michigan growers to work in. You are likely more
acclimated to higher temps. Separate climate controlled area for trimming - or off premises suggested.
4. Michigan caregivers are still being raided. If one too many clones puts you over 72, or if one too many grams
of finished product (15oz max) they take everything. So investing the minimum in infrastructure for cargivers is a priority.
They are even taking the AC units outside in some cases. But with the new licenses, that is prohibited so they can look at
normal investment/payback periods. I only mention this because I am unfamiliar with how Florida law is written. Consider
curing/trimming at a separate location if there is any concern. Growers A&B above are doing this because they need to
nail down the lighting scheme for the licensed grow so they can design the facility.
5. NOT 1 light per plant. I had a hard time getting growerA to understand that if they are spreading their plants out
farther due to crowding, DON'T spread the lights out further. For optimal yield with CO2, you need the high light intensity.
Complicating this is their method which involves not only horizontal screens but vertical screens hanging from the ceiling
on either side of the HPS & plants. Retrofitting LED fixtures in a continuous harvest set up like this is a real pain.
With LED, think field of lights up there at there optimum spacing with plants below at their spacing.
Bring any support infrastructure from below.
6. GrowerA's HPS program involved using some sort of dual $HPS/MH$ bulb for the first few weeks of bud
to reduce stretching. They saw little benefit after those first weeks so would switch them out for lower cost 1000w HPS for
the remainder of the time to save hours on the pricey HPS/MH. With the LED lights The excessive stretching didn't happen.
7. One big benefit of the LED COBs is light adjusting routines & infrastructure. The LED lights have
Bridgelux Vero 29 4000k COBs 80w at 14.5" spacing. Each fixture 9 leds.
On a field install, we get pretty much 1380+- PPFD everywhere at 18", 1200+- PPFD at 36", 1080+- at 48"
What does this mean? No light adjustment needed. Hang them 6-12" higher than final plant tops and
leave them. At the perimeter of the light field, use reflective solution - and keep it close.
No 3' away on the other side of a walkway. In the above side by side, I was sort of concerned after the install was done
and plants were just in - the lights looked ridiculously far away. In the end, it didn't matter.
With the lights that far away, spending a lot of time keeping the canopy even is considerably less important.
GrowerB above has stopped worrying about the canopy evenness and eliminated having walking corridors between
every other row of plants. This is key. Lights don't just light the plant below but the ones adjacent. Add 2' aisles and
there is a major drop in PPFD on both sides of the aisle.
But if you don't need to adjust lights, don't need to even out the canopy, have the plant well trimmed as it goes into bud,
don't have broken down light movers to access and you have the good penetration we are getting, you can go isle free
which means that with the light field installation, you might have 20% more plants which more than offsets for the
additional trimming at harvest.
None of this is a big issue with a small grow but with 500 or 1500 plants, if you can reduce the time spent per plant per week
by 10 minutes, with a 500 plant license, you just eliminated the need to hire 2 additional full time employees, 1500 = 6 full timers less
while having 20% more plants. A worthwhile trade off.
8. Chinese lights... Be careful. They range from overrated, quick lumen depreciation, led burn out models to better.
You say Chinese lights but not sure what you mean. I wouldn't be surprised if Cree's and Bridgelux were made in China but
they have QC standards beyond just the minimum needed to get product out the door. If a fixtures components don't have a track record
like genuine Meanwell, Cree, Bridgelux, due diligence is in order. GrowerB above has partial failure on 4 of the 8 blurple fixtures he bought.
9. Do not make a decision to go LED or HPS until you have done it yourself. You are looking at a major investment and need to
have results you can trust. Growing indoors CO2 is a very different ballgame than outdoors. Set up a test tent and see how the Chinese
fixtures work out. Just make sure you space your lights so that you are getting the desired PPFD regardless of what the manufacturer
Thanks so much for this information. Actually i have some interesting news. We as of right now have decided to move to Oregon to start our business. All things considered it just makes more sense there. First there are no residency restrictions. 2. I is legal for recreation there. 3. we can get our license to grow while still out of state are long as we purchase the land. 4 can get a 4 bed home on 3 acres for 400k there.5 it borders 2 other states which are favorable to the business. We talked to some lawyers there today and we are going to have a Skype consult in a week to discuss our goals and to make a plan to move out there.
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