Before I drop a grand on a DIY setup some advice would be helpful.

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TaxesR4Loserz

Member
Wassup RIU. New Account here. I used to grow a lot of good weed back in the day, but life happened and I had to stop. Now with it being legal here I've discovered that the quality of herb is going down and as my username implies I don't like that 30% of what I pay goes to taxes that are used to actually continuing to police cannabis.

Initially I was just going to run a 4x4 with a dual cmh setup, but after reading a report done by my utility company on HPS vs LED for growing weed --Gavita 1000w DE HPS vs. SPYDRx PLUS and the LED won in quality and kept up with quantity-- I decided that an investment in LED lighting is worth it now.
In order to meet my daily usage of about 12/oz-1oz per day I've decided to grow in a 5x2.5 tent with two 2x4 trays with 18 plants in 1 gallon smart pots (coco) on each of the two trays stacked vertically on a 48"x18" rack. CO2 will be maintained at 1500-1700ppm, and since I'm going to keep temps at 85F simply venting with a 6" fan on a thermostat with CO2 replenishment should be easy. I'll have a dehumidifier as well.

I am almost certain that I am going to be using strips to do this. I am thinking that I should split the two rack into first half and second half of flowering spectrums. For the late flower, which would be on the bottom rack, I would be using 6x Nichia 757 97 CRI boards from Cutter powered by an HLG-320h-48, and with 8x Nichia 757 2000k boards also from Cutter again powered by an HLG-320h-48. The top rack will have 10x the Cutter Cree JK3030 3000K 90 CRI that will be powered by an HLG-480h-48. I'm going to use aluminum c channel as the heatsink/mount with thermal tape to mount.

Is it reasonable to expect to get a DLI schedule down so I only have to run the lights for 10 hours at those conditions? In other words, is my assumption correct that I will be able to dial down the power as necessary while maintaining a 9" distance from the canopy of both trays to hit that balance? While I could still run 12/12 I'd like to only run for 10 hours of light so that I can benefit from be entirely in the cheapest time of day to use it, and since my temps are going to be warm that means I'll be able to directly vent in cooler air from the outside while being able to shut it down just in time to get really cool air in the tent for the plants sleepy time.

Are there reasonable alternative boards out there? I've looked at quantum boards, but I'm not sure they're exactly what I need for this application, so am I wrong? Is there anything else I should be considering? I don't think COBs fit this application, and I could run a sea of burple over the sea of green, but I know better from reading what a lot of you have already written. Maybe I should just do a 4x4 with a SYPDRx PLUS? I'd like to think that I can do better.

Thanks and Peace!
 
nfhiggs

nfhiggs

Well-Known Member
I'm not a huge believer in "fine tuning" the spectrum - a good white light in sufficient intensities is going to grow just as good as any another, within a few percentage points - obviously not too blue heavy for flower though. The Samsung F series, IMO are a reasonable alternative - 44" strips run $28 USD and are 8800 lumens per strip at test current. 6 of them at 50W each would match up well with the driver you mentioned.
 
Sour Wreck

Sour Wreck

Well-Known Member
i am currently running 4 plants under my DIY f-series strips, 50w each. i am driving 10 3500K strips and 6 3000K strips with a HLG-480H-48A. 16 strips for 800watts total.

this will be my first run with them in this configuration(all overhead, roughly 4" apart) and in RDWC. i expect very good results.

plants have been in 12/12 just about a week and are very happy.
 
T

TaxesR4Loserz

Member
Humple said:
Do I understand correctly that you're planning 600+ watts over a 2x4 area?
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It would be two 2x4 trays stacked on top of each other in a tent. My target energy use is approximately 300 per tray. Think of it as adding a second story inside of the tent. I’m hoping that maybe I could get it lower. I was looking at the Q strips. 12 of them for the first half of flower so that would only be 240 Watts for tat tray and 280 Watts for the last half of flower tray.
 
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1212ham

Well-Known Member
I'm not one of the experts, but 44" F-series strips on c channel is excellent. 3500k works well for veg and flower, but I'd consider 2 lights and drivers just for flexibility, and you could use different color temps for veg and flower if you like. At any time, you could also supplement with some far red or uv etc. Running drivers on 240V is 3-4% more efficient and I'd definitely get drivers with dimming.

The Q strips are more efficient but lower power, so that means more strips and wiring etc.
 
Porky101

Porky101

Well-Known Member
LEDS are the BOMB!!!!

There are many different kinds of LEDS, make sure you get a good type of COB or SMD setup and you cant go wrong.
 
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1212ham

Well-Known Member
All the LEDs mentioned are excellent. ;)

280 watts for 2x4 is good, but wouldn't you want more with co2?
 
Porky101

Porky101

Well-Known Member
1212ham said:
All the LEDs mentioned are excellent. ;)

280 watts for 2x4 is good, but wouldn't you want more with co2?
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How many watts of LED is needed per sqm?

Im running around 600W LED PSQM....seems high? not having heat issues...
 
T

TaxesR4Loserz

Member
1212ham said:
All the LEDs mentioned are excellent. ;)

280 watts for 2x4 is good, but wouldn't you want more with co2?
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I was thinking that. So far my choice of boards has been based on the efficacy of the chips. I've already emailed Cutter about them, and they did a simulation and came back with figures based on using 16 of the boards in a 4x4
I ran some simulations on this scenario. Couple of pertinent points:
  • The 2000k and Optisolis leds are great spectrums but you take a hit in efficacy, this is not a criticism but for great spectrum it is harder to get the photon numbers
  • I ran this based on 16 boards but then dropped two centre strips to boost the centre as I was pushing out the strips to get as even a photon coverage as possible
  • This equated to around 450-500 watts so another 100 watts of strips(other than cost) would not make it a bad deal
I got centre reads of 1500 PPFD at 7 inches and then more like 1200ppfd away from centre with absolute corners at 7-800 PPFD, average across the space 1287PPFD, an extra 4 strips would definitely improve this but would likely require a less symmetric layout to optimise photon coverage
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So I would be pushing it towards the bottom of what Mark suggested, but that's what a dimmer pot is for, right? My target was 1600 PPFD at 9", so I think that it will be good because of CO2.
 
T

TaxesR4Loserz

Member
Porky101 said:
How many watts of LED is needed per sqm?

Im running around 600W LED PSQM....seems high? not having heat issues...
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I'm going to be running CO2 at high PPM so I have the tent at 85F, and it would be inside a house that has central heat an air keep the temp at either 68 (winter) or 78 (summer). The math adds up to about 600w for 1.5 square meters. 2ftx4ft = .75 square meters x2.
 
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1212ham

Well-Known Member
TaxesR4Loserz said:
I was thinking that. So far my choice of boards has been based on the efficacy of the chips. I've already emailed Cutter about them, and they did a simulation and came back with figures based on using 16 of the boards in a 4x4

So I would be pushing it towards the bottom of what Mark suggested, but that's what a dimmer pot is for, right? My target was 1600 PPFD at 9", so I think that it will be good because of CO2.
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I'd say 600w is good for a 4x4 without co2. 1287 PPFD sounds high from 500-600w in a 4x4, but I'm sure the light guru's will be along to enlighten us.
@Randomblame, lay it on us brother.
 
Randomblame

Randomblame

Well-Known Member
If you stack two trays vertically in a 6,5' high tent you'll actually have two 4x 3,25' vertical area's to lit up. 600w should be okay and you can still dimm it down for the early stages.

@T-Time does something similar. Maybe you can get some tipps from his thread useful for your own pourposes.

https://www.rollitup.org/t/5x5-led-t-time-grow-time.949945/

Good luck!

BTW, I'm not a friend of different spectrums for different stages. Veg and bloom is enough. Remember plants always have to adjust them self to new conditions. I've seen lot's of people getting issues when switching from weak coolwhite to intense warmwhite and it takes a few days until they recover(not only with LED). 3000-4000 ° K has been shown to contain enough blue to produce stout growth. 2000 ° k may already contain too little blue, causing unnecessary stretch. You don't need that with a stacked system like yours. I would prefer 3500 or 4000°k/CRI80 to keep the plants short, strong an bushy and to fill both trays completely.
 
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Randomblame

Randomblame

Well-Known Member
TaxesR4Loserz said:
I was thinking that. So far my choice of boards has been based on the efficacy of the chips. I've already emailed Cutter about them, and they did a simulation and came back with figures based on using 16 of the boards in a 4x4


So I would be pushing it towards the bottom of what Mark suggested, but that's what a dimmer pot is for, right? My target was 1600 PPFD at 9", so I think that it will be good because of CO2.
Click to expand...

1600μMol/s/m² and 9" distance will probably cause a hell lot of problems. Bleaching, Mg deficits, heat stress, VPD too high... Also with CO² thats to much for such a short distance and it would be tricky to keep the plants healthy.
I would go with <800 without and >1000μMol/s/m² with CO² but not more than 1200 max..
 
Porky101

Porky101

Well-Known Member
Randomblame said:
1600μMol/s/m² and 9" distance will probably cause a hell lot of problems. Bleaching, Mg deficits, heat stress, VPD too high... Also with CO² thats to much for such a short distance and it would be tricky to keep the plants healthy.
I would go with <800 without and >1000μMol/s/m² with CO² but not more than 1200 max..
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I agree with what is said above, from experiance, above 1,000 umols you get spots that look like CA def. Also seems to slow flowering time and reduces yield.
 
1

1212ham

Well-Known Member
T

TaxesR4Loserz

Member
Randomblame said:
1600μMol/s/m² and 9" distance will probably cause a hell lot of problems. Bleaching, Mg deficits, heat stress, VPD too high... Also with CO² thats to much for such a short distance and it would be tricky to keep the plants healthy.
I would go with <800 without and >1000μMol/s/m² with CO² but not more than 1200 max..
Click to expand...
Thanks for your input. The SPYDRx PLUS I’m the study I linked to in my original post was measured by SMUD to be putting out 1323 PPFD at 6 inches with a CO2 concetration that went from 800PPM and maxed out at 1400PPM the RH was steady at 55% with steady temps of 80F so a VPD around 15-16. I know that there is still room to push the limits by raising PPFD, CO2 PPM, RH, temps, adjusting nutrients and irrigation cycles to compensate for increased transpiration to hit the limit of what the plants will be able to take. So do you think that I would be at the appropriate intensity to run DLI based timing to shorten my lights on time to 9 or 10 hours?

Yeah I know that when you have plants pumped up like Lance Armstrong during his Tour De France streak that taking care of them becomes more difficult. Things that would normally take days to happen take hour instead, but the corollary is that an experienced grower will be able to recognize the issues sooner and reverse them faster as well. If this were my first dance, then yeah I would stick within your suggested ranges.
 
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