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Grow light test

W

wordwiz

Next week, I will be getting a 400 watt MH conversion bulb so I figure before the the indoor growing season begins, I want to determine the most efficient light to use. Efficiency wqill be defined as pounds of salable produce per kW.

The contestants:

On the east is a 125-watt LED panel, said to replace a 400-watt HPS. It features red, blue and orange lights in a 8:1:1 ratio. On the west is a 400-watt MH/HPS set-up from HTG Supply. The lights will be hung at a distance that allow me to cover the advertised growing area (about 3'from the floor) but plants will be set on whatever I can find to get them as close to the lights as possible without heat or a loss in Lux occurring.

The test plants will be two types of toms, a Celebrity (determinate) and Better Boy (indy). They will be grown in 4-gallon plastic buckets using Tomato-tone as the nuit. All liquid will be provided from a common container (a 35-gallon plastic can) so the pH and ppm will be the same. The lights will run from the same timer (13 hours/day) and the same air pump. They are in the same room, so the temps will be nearly identical. Both grow areas are lined with Mylar, though not all the way to the floor.

Have I overlooked anything?

Mike
 
care to share your location?

I ask because you said "indoor growing season". This sounds like a cool experiment. Are you using toms as guinea pigs for next year's chiles?
 
salsalady said:
care to share your location?

I ask because you said "indoor growing season". This sounds like a cool experiment. Are you using toms as guinea pigs for next year's chiles?
Click to expand...

Cincinnati. This is a test to see how well tomatoes will produce. I would like to grow at least 28 plants this winter, maybe 56. It will also give me a good idea of how long it will take to produce ripe fruit and perhaps even a hint toward expected production. I need two pounds per plant per week.

lazienfat said:
Thats awesome cant wait to see the results. Any pics?
Click to expand...

Not yet. Just ordered the MH bulb!

Mike
 
One each of Celebrity, Better Boy and Legend tomatoes, two Nankeen Cotton plants under each light.

Same nuit solution, same air pump, same size containers. Same air temps, plants in their own area where no light from the other one can affect the other one.

One thing that surprised me it hot much hotter the MH bulb is compared to the HPS.

Updates will follow!

Mike
 
It's only Day One, but I've noticed a couple of things:

The Better Boy tomato plants seem to have a hard time getting acclimated to water. Both are still very wilted, though I don't know why they would behave differently from the Celebrity. Both grew up under the same light, were the same size, are under the lights in the same place. The plants under the LED light seem - and it is very early - to be a tad more leggy than those under the MH. The exception is the cotton plants; those under the LED seem to love it. The Legend tomato plants, that have spent the last month outdoors, seem to be adapting well. They have become a lot more green in just a day.

I added a small fan to each set. Not exactly the same, but close. One is a converted 1500 watt heater whose heat wire was disconnected. The other is a 1200 watt heater that has a fan only setting. I figure it will make the stems a bit stronger as well as help dissipate some of the heat from the MH bulb.

I'll be on Cloud Cuckoo if I get 120 pounds of toms from the six plants!

Mike
 
Toasty,

I haven't grown Better Boy or Celebrity before. The Legend has a good taste but is not a prolific producer. I had a spot under each light and had the plants so decided I might as well try it.

The Better Boy was from extra seeds - unless it does extremely good I probably will not grow it this fall/winter, as it is an indeterminate and my ceiling is only 6' tall. The Celebrity is suppose to be a fav of people growing for Farmers' Markets - tasty, nice size, great production. It is also a Determinate so I shouldn't have to worry about the height.

Mike
 
Well, my first couple of weeks has been anything but a success. Not a shock - first, I used homemade nuits that probably are not suited for hydro and secondly, I tried to transplant potted seedlings into water. Pretty much a crash & burn! :(

But, if I really want to raise 100 indoor plants this fall & winter, I need to get this down. So I started seeds in rock wool cubes and bought some hydro nuits (EcoGrow and EcoBloom) that I used in the past.

On Wednesday, four Celebrity seedlings were moved to their buckets of water, two under the MH light and the other two under the LED. They all have the same nuit levels, the light cycle is the exact same and one pump supplies the air to all the buckets.

Despite the short amount of time that has elapsed, I can see a bit of a difference. The MH plants are maybe 25 percent bigger than the LED ones.

Of course, there are still at least 90 days to go!

Mike
 
wordwiz said:
I tried to transplant potted seedlings into water. Pretty much a crash & burn! :(
Click to expand...

Absolutely nothing wrong with doing this. I have two superhots in an Autopot system that I had originally grown in pots with soil during the summer. All I did was try and remove as much dirt as possible, and stuck in the Autopot with perlite & vermiculite. They are now about a metre tall, but it's too cold for pods to form even in the tent with a 400W lamp. Watch out when the weather picks up though, given the amount of flowers I am dropping these things will go nuts all of a sudden when the overnight temps pick up.
 
would love to see pics of your setup, i am very interested in following this thread, gotta get some ideas for next year :dance:
 
The plants have been in their buckets for about a week now.

The LED plant (one):

LED1.jpg


The MH plant (one):

MH1.jpg


These were the same size when moved to hydro. I have two others that were a bit larger in the next post.

Mike
 
I sent the results to the lady who sold me the LED panel - I told her I would keep her informed because she sold me panel at an unbelievable price. She told me they are building some new panels: two spectra each of red and blue, some orange and some white. If the price can stay reasonable, this could be a serious grow light. I would like to see a few purple and even a couple green and yellow. Yeah, plants don't use much green or yellow but there is a difference between much and none.

What I don't understand - they have high intensity LED billboards that can display (I'm guessing) 256 colors, with the pictures being controlled by a computer or chip. So why not build a smaller version that the grower can control? Cycle through all the colors, all 256, concentrating on the spectra plants use the most but also incorporating all the others.

Yeah, these BBs cost thousands of dollars but they can be read from 500 feet away - in daylight, so the light intensity has to be great. Downsize it so it can be read from two feet. Instead of 20'x40', make it 1'x3'.

I wish I had the knowledge to build a panel. I would have lights pot growers would envy!

Mike
 
lazienfat said:
the MH is going to own!
Click to expand...
This test - no doubt. The difference between yesterday and today is amazing. But... if Jessica builds the right LED panel, and - a BIG if - it is comparably priced, I suspect it will be the winner. It's just a matter of adding all the right spectra!

Mike
 
wordwiz said:
This test - no doubt. The difference between yesterday and today is amazing. But... if Jessica builds the right LED panel, and - a BIG if - it is comparably priced, I suspect it will be the winner. It's just a matter of adding all the right spectra!

Mike
Click to expand...

Yeah I suppose, the whole light spectrum thing can get pretty confusing, I am glad your doing all the leg work and will let us know the results :D
 
Yeah I think I too got my money on the MH. I also kind think of it this way "If its supposed to be all that great why isnt everyone doing/using it?" Well in this case our high 420 cousins and even produce growers and many others are using MH all over the place. MH is expensive which I think is the ONLY reason or one of very few reasons that people consider LED.
 
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