First Soil Grow, 3x3 tent w/3 Plants, 420 watt 3D Printed LED [Bubble Gum, Gorilla Bomb, and Galaxy]

Discussion in 'Indoor Growing' started by []D[][]\/[][]D, Feb 3, 2018.


    []D[][]\/[][]D Member

    edit: I realize I may have posted this in the wrong forum, mods please move this to Grow Journals if that's a more appropriate place to post this.


    Bubble Gum
    Gorilla Bomb

    All from feminized seeds, crossing my fingers there's no boys.

    FoxFarm Ocean Forest Soil
    3 Gallon Fiber Pots


    GH Flora Series (yes I know its not the most organic or the best, but I want to use up my stash)
    GH Liquid Koolbloom
    GH CaliMagic
    Great White
    Unsulphured Molasses

    I built some incredibly cheap and effective lights, each 70 watt "auto cob" style light cost me about $10 each to make. With $60 or so in support electronics to run all the electronics.

    I found some $4.20 chinese "Full Spectrum Grow" 70w LED COBs and ordered a 6 for a total of 420 true watts. I run them in parallel in CV at a maximum of 35 volts, they run almost exactly 70 watts as advertised at 35v. The individual LEDs seem very well matched for once, when lit below 20 volts all LEDs in the cob light dimly and evenly, a very good quality LED COB from china for once.

    The heatsink/fan coolers are recycled from old computers ($5), the 3d printed parts are printed with ~32 grams of ABS ($0.57)

    The lights and exhaust fan are controlled by an arduino nano microcontroller and a real-time clock chip with battery-backup, I made a controller to configure it and log data, track progress, etc. But the lights and environment controllers run independent of being connected to the software controller.

    So far I am pretty happy with these cheap lights, I am running 4 out of 6 of the lights so far and the coverage is decent and intense. I don't think I will have any coverage problems with 6 of them. I am going to be experimenting with adding lenses soon, hoping I can raise them up a bit and increase useful coverage..

    This is my first time growing in soil and my first time growing from seed. I used to just run clones and mothers in hydroponics exclusively, but I have next to no experience with soil and seeds.

    Day 3 from seed, lights running about 60%. They stretched a little bit from being under a weak light earlier.
    The dual cob light on the left is a an early prototype . The single single cob light on the right is one of the newer iterations. All of the non-enclosed electronics viewable are only in temporary positions, I have a completely enclosed remote lighting control box almost ready for integration. The highest voltage found inside the tent is 35 volts for the LEDs.


    Day 23 from seed. Lights running at 80%.

    The plants are very short and packed with nodes, I topped them on day 21 and begun LST when the new branches began to shoot up. I will take true-color close-ups when the plants begin to open up a bit more. This spectrum and intensity seems to be inhibiting stretch, there is at least 10 tops near the canopy of each plant, I think they will begin to stretch out more soon. I plan on switching to flower in 1-3 weeks.

    Prototype control board:

    Here's a screenshot of a very incomplete version of my control software.

    So far so good, I will post updates in a few days or the next time something interesting happens. Feel free to make comments or ask questions

    BushMaster15 Well-Known Member

    Nice! Pretty cool that you engineered all of that yourself.
    []D[][]\/[][]D likes this.

    psychedelicdaddi Well-Known Member

    so whats going on with your electronics? Is the arduino nano being used as a timer or some kind of data conversion from a different source? what is the 8pin DIP and whats this little blue guy on the right?
    []D[][]\/[][]D likes this.

    []D[][]\/[][]D Member

    The nano is being used as a light timer, environment controller, and data logger interface. Every second the nano checks the time and checks that the lights is in its proper state. Then it reads the temperature and humidity and writes it to the serial port. I wrote a library and companion program in c# to monitor the serial line and configure the nano / send commands to the tent.

    The 8 pin DIP package is a DS1302 real time clock, the crystal and battery are it's companion components, this ensures that if the power is ever lost the time won't be lost.
    The blue module to the right of RTC is a DC-DC 5v buck converter, it allows me to connect the electronics directly to the 24 volt power supply

    There is a DHT22 temperature+humidity module hanging inside the tent and some soil hygrometers.
    The lights are switched using a cheap 40amp DC SSR

    The idea of the software is to incorporate a whole grow journal and scheduling system.
    Once I am moderately happy with it I will post everything as open source in case anyone else wants to play with it

    []D[][]\/[][]D Member

    Day 26 from Seed
    I opened up the canopy as best I could, but these plants are still growing like super dense lettuce, it is as impressive as it is annoying but they should stretch out more. It would seem that the insane intensity combined with this spectrum are minimizing all stretch leaving the plant to focus on bud site production. A few of the larger branches were topped at this stage to promote branching.
    day 26.jpg day 26-2.jpg day 26-3.jpg

    Day 31 from Seed
    Got a little more stretch, I was able to increase the canopy size to roughly 1 sqft per plant. More branching to the top from the topped branches as expected. Increased budsite development on main stalks.
    day 31.jpg day 31-2.jpg day 31-3.jpg day 31-4.jpg day31-5.jpg

    Day 33 From Seed
    (today, 2/12/2018)
    I plan on switching to the flowering stage in the next couple of days. In preparation I have installed another 70Watt "3DCob", it is my (near) final design with the entire light and heatsink assembly encased in 3d printed ABS plastic. I should have put vents on the front back instead of only the sides to increase airflow, but it is good enough as is. I will be converting all lights to the final design before I start my next grow. This run is experimental. I am running the lights at 91% power now, the temperature has risen a bit due to this and the additional light but is still manageable. The lights do not seem to cause any excess stress or burn from intensity. For a few days I accidentally ran with some hot spots at first with sections of the plants directly receiving 110,000 LUX in this spectrum without repercussions. It's still a bit early for me to declare these the future of grow lights, flowering will be the ultimate test.

    No true color images today, sorry for the bad photos, these lights wash out my camera phone's contrast.

    day33.jpg day33-2.jpg

    []D[][]\/[][]D Member

    Day 33 From Seed (continued from previous reply)

    Bonus Photo
    This is an internal shot of the electronics / controller box (sans control board). Designed to mounted outside of the grow tent.
    I think I will have some PCBs spun up to avoid having to make my own out of protoboard in the future.
    electronics box1.jpg

    []D[][]\/[][]D Member

    Sneak Peek for Next Grow
    ref.jpg lightbot.png

    []D[][]\/[][]D Member

    Just washed out purple photos today, it's the best my camera phone can do. I will take proper color corrected photos when they look more interesting and fill the canopy more. This camera phone is very nice, but they do not know how exposure or anything to adjust for this light spectrum at all

    Day 2 Flower
    (41 from seed)
    Installed a scrog net, they have been receiving a half-dose of the GH flora series, calimagic, and molasses (and an occasional dose of great white). Trying to open up the canopy a bit, the plants are about 5-6" in vertical height, the canopy is low so bottom branches have a chance. I was hoping to get a bit more stretch on the auxiliary branches in veg but it didn't happen, I expect them to stretch out during the beginning of flower.

    Day 3 Flower
    They are very very bushy, they stretched about an inch since yesterday, I won't be pruning them again until they complete their stretch.

    []D[][]\/[][]D Member

    Day 8 Flower
    Flowers starting to form, the plant's preparing to begin the big stretch. I started adding GH Liquid Koolbloom. All nutrients are still at half strength.

    Day 14 Flower

    The girls they stretched a couple inches overnight. The Gorilla Bomb is towering over the others, It is now the tallest of the three plants at 12" tall.


    Gorilla Bomb is very long
    flower14-3 (2).jpg

    []D[][]\/[][]D Member

    Day 17 Flower (14 days before it gets really interesting)

    One of my lights started to overheat on the 16th day, it was not too unexpected, that particular light had a small heatsink with a weak fan. I replaced it with my lensed version as it is all I had on hand. The lensed light seems to do a pretty good job achieving the insane intensities I'm going for. I can get an even 70000 LUX (measured with garbage) spot light in a 10 inch diameter circle. It easily covers the area the old light did, except it's actually more intense. Another plus is since the light throw is further the lower nodes in the canopy receive more intensity. Some drawbacks I see is the area seems to be physically hotter under the lens, there is obviously some light lost/potential efficiency lost, and the beam angle is so narrow that less light diffuses off my reflective walls.

    Growth is still massive, the tops continue to grow and stretch ~1-2 inches per day, most of them are packed with bud sites that go 10-14 inches down the stem, especially the gorilla bomb. Bubble gum is taking up the 2nd in terms of production and galaxy is probably going to be the lightest. This is probably due to uneven lighting on the galaxy plant. The distance from the soil to bottom of the canopy is only a few inches so most of the lower branches easily reach the canopy. Node density is incredible, I hope they fatten up and don't burn on me under my stupid intensities. So far I have had a flawless run (except for the light but I don't consider that a setback). I'm still running at 343 watts.

    I'm open to any comments, suggestions, questions, etc.


    Temps have been okay with 72 degrees in the dark period and high of ~82 during the day, although when the light went thermal runaway on me the high reached as high as 87. Humidity has been a solid flat 40% shortly after flowering began.

    Honestly I haven't worked on control/journal the software too much, but I do use it all the time to track temperature and humidity, and to change the light schedule.
    You can see the dips in the chart from when I open the tent, I think I need to upgrade my ventilation fan, it is pretty weak.

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