All COB Users - Lettuce Grow Challenge!!

PicklesRus said:

He's so little - took a while to get him There didn't it?

You can grow him really big

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I have only had it from the nursery for 2.5 weeks I know they can get big the topping has already begun lol At my house back home I started my basil and oregano in mason jars and they're monsters out in the ground now

This was the day we brought it home on 3/13:


The picture in the previous post was today there was slim pickings still at the nursery when we went that day but I wanted to start some non mmj stuff again I like to grow various plants especially fruits and veggies. had my yard full of fruit and veggies back in FL

RandomHero8913 said:

Hey guys, I've got everything set up for the 90CRI different CCT lettuce test except the grounding part. All my other fixtures are built around a frame to make one unit which makes grounding easy. This run I'm using five 105mm pin heatsinks with a piece of angle aluminum on opposite sides so I could hang them with eyebolts. I'm powering all 5 with 1 driver and my question is this: Do i run a grounding wire to each heatsink?

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Can you test conductivitity between each farthest cob to see how well electricity travels through the frame? Would that tell you how much grounding is required?

Update today

I didn't cover the rockwool cubes so there's mold and algae growing on top of them I can try to clean that up and cover them.

Pickles, I think I may have poorly explained the setup. Here is a picture.


So with the setup like this does each individual heatsink need to have a grounding wire ran to it? Or would it only need to be grounded to one?

Thanks

RandomHero8913 said:

Pickles, I think I may have poorly explained the setup. Here is a picture.

So with the setup like this does each individual heatsink need to have a grounding wire ran to it? Or would it only need to be grounded to one?

Thanks

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Aren't they all connected with metal already? Seems like it to my stupid eyes lol.

And wow! Just motherfucking wow!

RandomHero8913 said:

Pickles, I think I may have poorly explained the setup. Here is a picture.

So with the setup like this does each individual heatsink need to have a grounding wire ran to it? Or would it only need to be grounded to one?

Thanks

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This is shaping up to be the best test I have seen yet using cob tech
What varieties will you be using?
Some butter crunch head forming type would make for some solid data
Keep up the good work!

I am really digging red sails from johnny seeds, very large leafs and produces a lot. I thought i had some weird issue , but it turned out my lettuce was just turning red.

PicklesRus said:

Not sure if it's too soon to tell but I think that having only two LED strips above the plants doesn't give enough exposure from different angles to develop a nice canopy...

or my lights should be closer

It's reading around 100 PAR at the edges to 250 in the middle. I don't think that's quite good enough. It's only around 9300 lumens. I'm going to up this shelf back to 20,000 lumens and build another at 15,000. I'll also hook up my trusty three Philips production modules on another level

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looks great! that red romaine is rock solid, after most of my plants have started dying, the red stuff looks fresh still. It just grows forever.

RandomHero8913 said:

Pickles, I think I may have poorly explained the setup. Here is a picture.

So with the setup like this does each individual heatsink need to have a grounding wire ran to it? Or would it only need to be grounded to one?

Thanks

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Well that's why I was wondering - it looks as though electricity out into the far left of the support rod would definitely travel to the rest of the metal, so you would think that you only need one grounding wire.

RandomHero8913 said:

Pickles, I think I may have poorly explained the setup. Here is a picture.

So with the setup like this does each individual heatsink need to have a grounding wire ran to it? Or would it only need to be grounded to one?

Thanks

Click to expand...

That is amazing!!! i am super excited to see how this goes!! I didn't see a description on what you have there. I think this may actually be the first real cob test i've seen here. At least one to this scale. Can you give massive amounts of details on what you have, how you are going to proceed, lettuce types, nutrients, really everything.... just awesome....

Of course.

1. Lights
- Clu048-1212 Gen 6 90cri COBs. I'll be testing 2700k, 3000k, 3500k, 4000k and 5700k, thanks Cobby!.
- Ledil Angelina 30° lens, Ideal COB holders and lens adapter.
- 105mm heatsinks from Northerngrowlights.
- HLG-60H-C350A. I'll start them at the lowest setting of 210 and see what happens.
- Cheapest 3ft sections of aluminum rods I could find at home depot, they happened to be threaded.
- Optional- I have the RZ sublens for the angelina reflectors and I may pop them on.

2. Soil / Nutrients
- Some peat based soil I made last year based off of Coots recipe. Organic.
- I think I'm just going to be watering and thats it. I don't think I'll need any teas or topdressing for this.

3. Growing Area
- The boxes are about 1'x1'x2' LxWxH. All home depot cuts so shit ain't exact.
- I'm going to cut some cardboard and use it to block any light spilling over from my other lights in the top left of the pic. That will hopefully prevent any light contamination and allow me to keep accurate results.

4. Lettuce
- Right now I only have some Buttercrunch planted. I'll be starting other varieties and adding them in later.

If I missed anything please feel free to ask.

Got the lights up and running. Doing a temp test.


As you can imagine it's 2700k, 3000k, 3500k, 4000k and 5700k,
That is a big ole difference between the 4000k and 5700k

PicklesRus said:

View attachment 3916590

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You might suggest considering some kind of nutrients with the lettuce. I wouldn't go and buy super high end stuff, just some some dry stuff like...

https://hydro-gardens.com/product/lettuce-formula-5lbs-box-8-15-36x5/

i'll assume as a well-known member you are an experienced grower. so I won't talk ph/ec/cal/mag.

I planted some bibb lettuce, like buttercrunch, it did NOT go well. All my other types did great. So I'm double excited to see how this goes now.

are you going to be tracking how much light the plants get each day? Once things get rolling good, I'd be curious on your light cycles.


edit:

AWESOME PICTURE!!! love how the light changes so dramatically

I have a bunch of dry ingredients handy if I need to perk them up.

The lights will be on a timer so they will all get the same amount of light. Do you have any recommendations for hours of light. I was going to keep it the same as the other light in the room but that would be around 16 hours and I'm not sure about the whole bolting aspect of this lettuce.

RandomHero8913 said:

I have a bunch of dry ingredients handy if I need to perk them up.

The lights will be on a timer so they will all get the same amount of light. Do you have any recommendations for hours of light. I was going to keep it the same as the other light in the room but that would be around 16 hours and I'm not sure about the whole bolting aspect of this lettuce.

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its really hard to say. It depends on how much light they are actually getting. If you give them too much, they will get pretty bad tip burn, If i can find it, there is some crazy formula that would get you a general idea on how much light to give them. I think Cornell U suggested like 16 mols a day. so there is a conversion from LUX to mols, there are like 3 or 4 conversion steps between the 2. Are you doing one plant per stall? If so, i would think 16 hours will be more then you need. Less seems to be more in the lettuce world. Also, the no/little nutrients thing is making me apprehensive.

how many watts do you think you are going to be expending per light?

RandomHero8913 said:

I have a bunch of dry ingredients handy if I need to perk them up.

The lights will be on a timer so they will all get the same amount of light. Do you have any recommendations for hours of light. I was going to keep it the same as the other light in the room but that would be around 16 hours and I'm not sure about the whole bolting aspect of this lettuce.

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Take your light PAR levels and use that to calculate what the DLI will be at different intervals example 16h, 18h.

Then you can check what DLI is recommended for your crop. Lettuce has a lower DLI than others.

LX to MOL (quick)

LX * .001253232 = mols (for a day)
LX * .0000522 = mols (per hour)

so using the example below

20000 * .001253232 = 25.06464
20000 * .0000522 = 1.044

Formula to convert LX to MOL (long version)

For this we are going to assume that LX x .014505 = umol

So you have a light and at a given spot you get 20,000 LX

so 20,000 x .014505 = 290 uMols

convert below:

http://www.convertunits.com/from/umol/to/mols

290 uMols = .00029 Mols

.00029 Mols x 60 seconds = .0174
.0174 x 60 minutes = 1.044
1.044 x 24 hours = 25.056

.00029 * 60 * 60 * 24 = 25.056

Cornell Univ suggested like 15 or 16 mols a day so you would run your lights for around 15 hours a day.

15.5 / 1.044 = 14.84 hours

Again, this is based on the LX x .014505 = umol conversion being accurate (or reasonable accurate)

Organic, Sun Grown, Johnny Seeds Red Sails

Muleface, it looks like running the lights at 350ma is just below your example calculations so keeping them on the 16 hour schedule will work. Thank you, I appreciate your input with this.