Test 1: Greens, LED triband vs. CFL spotlight

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Test 1: Greens.

OY!!! the greens experiment LED light was 1/3 dead! :( :( :(


 

Note: This test was pooched by a hardware failure - LED light went bad. Please see Test 3: Greens for the rematch.

 

Constructed light isolation box for side-by-side growing (all same box, just rearranged):

Greens lightbox design. Left 16W triband LED, right 15W daylight 6500K CFL spot (built-in reflector).  Greens lightboxes planted and running. Radish, spinach, lettuce, mustard greens (3 plant families). Rearranged floor space, and swapped the planters/lights - the CFL is really hard on the eyes. 

Lights: 16 hours/day.

Today I found a CFL flood that was 16W... oh, well, 15W is close enough, I'm not going to buy more bulbs. For comparison, AG Deluxe bulbs are 26W, but unfocused. They also seem yellower to my eye.

The CFL is definitely hotter. Which will probably give the CFL plants a head start.

2009-01-23: Presoaked a couple hours and planted seeds in each of two pots:

  • 4 French blush radish (thin to 1 or 2) - harvest time 25 days
  • 3 baby leaf spinach (all others thin to 1) - harvest 30-45 days
  • 3 tendergreen mustard - harvest 30 days
  • 3 little Caesar romaine - harvest 45-60 days

In 9.4" diameter Misco self-watering pots (Walmart plant spa), and fresh Miracle Gro potting mix.

Hypothesis: My best guess :

  1. There is enough light to grow all 4 species, if somewhat anemically.
  2. There will be < 10% difference in harvest.

What I want is > 10% difference in harvest - LEDs clearly more grow power for same watts.

Anyone else want to bet?

Germination:

day 2: Most mustard greens and half the lettuces up. No real difference CFL/LED.

day 3: Three radishes up, both pots. One LED lettuce still MIA. Unfortunately both missing sprouts on the LED side are the ones centerward. All mustard up. No spinach yet.

day 4: Moved 1 outside lettuce into the light on LED side. Only 2 of 3 sprouted. Radishes have same problem - missing the seedling in the light. But I don't think radishes would transplant well.

day 6: Set some spinach seed to germinate in wet paper towels in a baggie. Will use some of those if the ones in pots fail to come up. (Not unusual for spinach.)

day 7: Final radish seeds germinated, one each side. (Not unusual for radish.)

day 11: Still no sign of the original spinaches. Planted 6 more from baggie sproutings, most advanced centerward.

day 14: First spinach emerged, one on each side (baggie sproutings).

day 20&21: Two more spinach emerged (first CFL side with no leaves, 2nd LED side looking good).

Progress:

day 5: Raised only LED light over greens. The spotlight was too concentrated in the center of the pot, with seedlings around the outside visibly stretching toward the light. CFL is not as focused, so raising it would entail a lot less light density at pot surface.

day 7: Lowered the LED back a bit. Maybe 3" higher than CFL now. The LED plants are stretched enough that they can lean into the light circle if they want.

7 days: greens. Lowered LED light a bit - the plants can lean in. 7 days, CFL side greens. 4th radish appeared. 7 days, LED side greens. 4th radish appeared, lowered LED light - seedlings can lean in. 

day 8-11: LED side brassicas keeling over. At first just one dark-side radish, but now 2 radishes and a mustard are lying down. Too leggy. The centermost radish (late sprouter in fullest light) is already taller than its CFL counterpart, and behind in leaf development. Best-lit mustard doing OK, but lagging all 3 CFL mustards.

day 14: Thinned. Didn't bother to weigh them. CFL side obviously better by far more than 10% - on the greens experiment.

14 day greens, with thinnings 14 day greens CFL side, after thinning. One spinach emerged today. 14 day greens LED side, after thinning. One spinach emerged today  14 day thinnings, mirrored CFL left, LED right, from top: tomato, radish, lettuce, mustard greens

day 21: Harvested brassicas. It's early, but the radishes were done, and the CFL side mustard was overshadowing everything - there were no questions remaining there. Left the lettuce and spinaches... for the moment.

21 days greens pre-harvest 21 days greens CFL side - mustard leaf is overshadowing everything. Dropped camera and broke half the leaves off the smaller radish... 21 days LED side pre-harvest - 2nd spinach up today 21 days - decided to harvest brassicas early (should have been 25 and 30 days) - roughly 7x biomass CFL over LED side (including radish leaves...)

 

 

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Ginger
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The dead LED lamp. I went

OY!!! the greens experiment LED light was 1/3 dead! :( :( :(The dead LED lamp.

I went back over my pictures (taken every day, just didn't post them here), and I can't tell when the lamp went bad.

Did learn a few things here, though:

 

  1. The 15W daylight CFL was bright enough to grow radish and mustard really well. I wasn't sure of that - the dimmest AG uses a 26W CFL.
  2. 15W CFL probably also bright enough for lettuce and spinach - those plants had other little issues.
  3. The surviving ~10W LED was not bright enough to grow well. However, the plants didn't die for lack of light. So... the experiment is in the right ballpark wattage-wise.

The revamped experiment will be same radishes and lettuce, but replace mustard with toy choi, and spinach with swiss chard.

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Yeah, I need to have a

Yeah, I need to have a discussion with HTGSupply. I've heard good things about that company - I hope for a replacement.

Seeds are soaking, Test 3 greens about to begin... Need to stop being mad at myself for not noticing sooner.

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Sorry about the LED, that

Sorry about the LED, that didn't last very long!

Hopefully you will now get comparable results to Test 2.

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Aw, hell! I thunk, "Eh, it

Aw, hell!

I thunk, "Eh, it wouldn't hurt to replace the LED lamp for the rest of the test. I have another."

The original LED lamp was one third dead LEDs. When did that happen...

Soaking more lettuce and radish seeds. Guess we'll try this again...

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Huh. That test was odd. His

Huh. That test was odd. His LED side got 20 hours light a day, CFL only 16, and non-comparable conditions. (CFL with heat mat (not something lettuce would appreciate) and moisture dome (moisture good for lettuce, but steam bath risk under so much heat/light), and he used a mega-powerful hot CFL, instead of equivalent wattage.) And his CFL seedlings don't look ill, just slightly smaller than the LED seedlings.

And his plants are just seedlings - any growth differential compounds over time.

My CFL bulb was 1/4 the price of the LED, unlike his. And cost the same electricity to operate.

My results so far are brassicas, not lettuce, though the writing is on the wall for the lettuce. Brassicas and spinach grow differently than lettuce, for sure.

< shrug> I could try it again with another of my LED lamps, since that was my only reservation - if maybe just that one lamp was bad. But I don't have any reason to believe that, other than that the LED tomato did much better. Or, I could try again with 2 lights on each side, so everybody hopefully has more than enough light. But what more would that tell me.

Edit: Gisette struck that last...

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Now that's a huge

Now that's a huge difference!

I was surprised to see the LED beaten so comprehensively, I have read that different plants need different light spectrums, but, the LED is a complete non-starter in this test.

In contrast, have a look here. Someone else has done a CFL vs LED experiment with much different results... We don't know if he used a reflector for the CFL or what sort of setup he had - no pictures of the grow!

 

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Three weeks'

Three weeks' progress:

Harvested brassicas. It's early, but the radishes were done, and the CFL side mustard was overshadowing everything - there were no questions remaining there.

21 days greens pre-harvest 21 days greens CFL side - mustard leaf is overshadowing everything. Dropped camera and broke half the leaves off the smaller radish... 21 days LED side pre-harvest - 2nd spinach up today 21 days - decided to harvest brassicas early (should have been 25 and 30 days) - roughly 7x biomass CFL over LED side (including radish leaves...)

I don't have a very good scale, and I broke off half the leaves on the smaller radish yesterday by dropping the camera. But remaining biomass was ~ 1.5 oz. CFL side, maybe .25 oz. LED size. So with missing radish leaves, maybe 7x (700%) better growth on CFL side. More if you count only harvest and don't like radish leaves. The LED side radishes would never have developed a bulb.

Left the lettuce and spinaches... for the moment. But in my experience it's 3-4 weeks from this point to harvest size on these plants.

21 days - after harvesting brassicas (mustard top, radishes sides) there's a second spinach seedling (up yesterday), but no leaves? 2nd spinach seedling up today. Truly pathetic looking lettuce.

Although I'm still a little curious about the spinach, continuing this doesn't seem worth the electricity. Question answered. Any other opinions?

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Two weeks' progress:    

Two weeks' progress:

14 day greens, with thinnings 14 day greens CFL side, after thinning. One spinach emerged today. 14 day greens LED side, after thinning. One spinach emerged today  14 day thinnings, mirrored CFL left, LED right, from top: tomato, radish, lettuce, mustard greens

Thinned today. Didn't bother to weigh them. CFL side obviously better by far more than 10% - on the greens experiment. On the CFL side, radishes are beginning to form bulbous stems - already split, actually. The brassicas on that side look great. The lettuce on both sides looks pretty poor. Maybe the air's too dry, or the soil too rich? 

This experiment is not going at all the way I expected. Lettuce was supposed to be the easy win, plant most likely to succeed. I wasn't sure the CFL side would have enough light for the brassicas. In practice, the brassicas are doing best of all, under CFL, and will certainly have radishes on day 25 as scheduled. The mustard looks fine, too.

And I expected both sides of greens to way outperform either side tomatoes. Not so...

It'll be interesting to see what happens with the spinach. But I'm not expecting much.

May call this experiment complete at 30 days.

Edit: I had a better picture of the CFL side radishes from yesterday:

Note center radish stem already fattening / split. Lettuce leaves not doing too well - too hot/dry?

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One week progress:    Note

One week progress:

7 days: greens. Lowered LED light a bit - the plants can lean in. 7 days, CFL side greens. 4th radish appeared. 7 days, LED side greens. 4th radish appeared, lowered LED light - seedlings can lean in. 

Note how much leggier the greens are on the LED side. CFL side has clearly superior seedlings. Though not much difference in development for best-mustard between the two sides.

But - having seen the 'clearly better' dishtub cuke just nosedive, we'll keep going with both sides of this experiment for now.

Edit: Although... if the CFL side had been the one stretching hopelessly, I would have added a bulb to see whether two equalled one of the other. Kinda pointless the other way around, though, since the LED spot is 4x more expensive than the fancy CFL bulb.

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7 days, still no spinach.

7 days, still no spinach. Hmph.

Found this discussion on GardenWeb and decided to try it. I need to start some spinach for outdoor transplants in March, anyway. (Finally found an answer to 'what exactly do they mean by as early as the soil can be worked?'. Lettuce & spinach supposed to go out 4-6 weeks before last frost, which is about March 1 here.)

Pre-soaked a bunch of spinach seeds (actually 2 bunches - two varieties) in cold tap water for a couple hours, in the fridge part of the time. Then wrapped them in cold wet paper towels and a plastic baggie, and placed on a chilly dark windowsill. Start checking for germination in a couple days.

Whichever 4-6 sprout first (including the ones already in those pots), get to be in the LED/CFL experiment.

Moderator. Author of Indoor SaladEcigs 102, and the Calm Act climate apocalyptic series.

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