Semi-tech --light spectrum for tomatoes - Page 3

ChrisK · December 13, 2015

Quote:

Originally Posted by Cole_Robbie

And there you have the reason why I can tell no difference between using cool white and day light bulbs. Whatever the difference is, it's not significant.

Greatgardens · December 25, 2015

A small update. Over the years, I've replaced all my old shop lights that have magnetic ballasts with new fixtures having electronic ballasts. At least for the ones I've purchased, they say "for T8 bulbs and also T12." Never gave that a second thought, and have used mostly T12's. But I just got some 6500K T8's and put in a pair and was very surprised to see how bright they were. So I did some research and came to find out that in all likelihood, these newer fixtures just under-drive a T12 with 34 volts, producing about 85% of the potential light. Not what I want for starting plants! So at least for plants, I'll use nothing but T8's from now on.
-GG

Ricky Shaw · December 25, 2015

T8's are are a good choice, higher lumen per watt and maintains light quality considerably longer than T12's

If a gardener's doing just tomato and pepper seedlings, and the added heat of T5's is not beneficial in some way, there's really no need to look further than T-8's.

loulac · December 31, 2015

I enjoy following the discussions between experts on the field of lighting even if I really can’t add anything on the subject. I’d like to make myself useful : If Tvillian experts are interested in the opinions of French growers about lighting they can visit http://tomodori.com/forum/topic12592-45.html The thread was started in 2013, you can directly jump to 2015. If your French is bit rusty just PM me the date of the posts you are interested in and the name of the contributor. I’ll send you a translation and you will feel free to improve my English and may post your version on Tville.

Greatgardens · February 27, 2016

Since I have revamped my lights for seed starting, my phone app says I am getting ~8500 lux (2 6500 Daylight + 2 Gro-Lux standard). But the rgb app portion doesn't work correctly with my Galaxy S5. Anyone using an S5 and an app. that correctly decodes rgb? How does the 8500 lux sound -- reasonable number?

Edit: I installed a new light meter app -- still just lux, but this one gives an instant reading + a graph of the past minute or so + the saved peak lux. I like this one better. This one is "Light Meter" for Android by "Keuwlsoft." It says my new lights are about 10K lux, and I also measured my old setup at just 4800. So hopefully I'll see some improved results. BTW, the Gro-Lux are T12 and the Daylight bulbs are T8.

-GG

RJGlew · February 27, 2016

Quote:

Originally Posted by Worth1

I'm going to put out about $24 for a 150 watt output 6500K LED and put it in a chicken brooder fixture jut to see what happens.

Hey Worth, how did this work out for you? Can you please post a pic?

Worth1 · February 27, 2016

Quote:

Originally Posted by RJGlew

Hey Worth, how did this work out for you? Can you please post a pic?

I never tried it yet sorry.
The last time I went some place it was all I could do to think of what I needed.
I might buy it today.

Worth

ChrisK · February 27, 2016

Good information in the presentations from experts in the field: http://leds.hrt.msu.edu/meeting/

loulac · February 28, 2016

Quote:

Originally Posted by ChrisK

Good information in the presentations from experts in the field: http://leds.hrt.msu.edu/meeting/

Big thanks for all the links given above. It will take me some time to explore everything, I've just started. I hope you don't mind if I send a copy of your post to the French site Tomodori, its experts will be delighted.

Some details about what is going on in France.
Growers seem to have adopted 20 '' long 7020 LED bars (10 bars are recommended = 8000 - 10000lux). The cheapest ones should be avoided.
- They receive 12 V DC, coming whenever you can get one from a discarded computer transformer giving in fact 11.5V when feeding a load. Wiring seems to be a bit tricky : plot 5 should feed a resistor to raise the output of 12V.
- Experts have summed up LED lighting in nurseries here : http://tomodori.com/wikitomo/index.p...s_en_aluminium
With Google Translate you may get understandable English...

Best regards

RJGlew · February 28, 2016

Quote:

Originally Posted by Worth1

I never tried it yet sorry.

No sweat, just thought I'd ask - I purchased a couple of offshore cheapies from EBay to get some exposure to them this year.

RJGlew · February 28, 2016

Quote:

Originally Posted by ChrisK

Good information in the presentations from experts in the field: http://leds.hrt.msu.edu/meeting/

Great site - thanks. Too bad that "Tomato transplant production under sole-source LEDs by Diana Vercillo, Grafted Growers" is a 404.

December 25, 2015	#32
Greatgardens Tomatovillian™ Join Date: Feb 2010 Location: Indiana Posts: 1,124	A small update. Over the years, I've replaced all my old shop lights that have magnetic ballasts with new fixtures having electronic ballasts. At least for the ones I've purchased, they say "for T8 bulbs and also T12." Never gave that a second thought, and have used mostly T12's. But I just got some 6500K T8's and put in a pair and was very surprised to see how bright they were. So I did some research and came to find out that in all likelihood, these newer fixtures just under-drive a T12 with 34 volts, producing about 85% of the potential light. Not what I want for starting plants! So at least for plants, I'll use nothing but T8's from now on. -GG Last edited by Greatgardens; December 25, 2015 at 10:16 AM.

February 27, 2016	#35
Greatgardens Tomatovillian™ Join Date: Feb 2010 Location: Indiana Posts: 1,124	Since I have revamped my lights for seed starting, my phone app says I am getting ~8500 lux (2 6500 Daylight + 2 Gro-Lux standard). But the rgb app portion doesn't work correctly with my Galaxy S5. Anyone using an S5 and an app. that correctly decodes rgb? How does the 8500 lux sound -- reasonable number? Edit: I installed a new light meter app -- still just lux, but this one gives an instant reading + a graph of the past minute or so + the saved peak lux. I like this one better. This one is "Light Meter" for Android by "Keuwlsoft." It says my new lights are about 10K lux, and I also measured my old setup at just 4800. So hopefully I'll see some improved results. BTW, the Gro-Lux are T12 and the Daylight bulbs are T8. -GG Last edited by Greatgardens; February 27, 2016 at 11:34 AM.

February 27, 2016	#38
ChrisK Tomatovillian™ Join Date: Mar 2011 Location: Raleigh, NC Posts: 1,448	Good information in the presentations from experts in the field: http://leds.hrt.msu.edu/meeting/ __________________ Blog: chriskafer.wordpress.com Ignorance more frequently begets knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science. --Charles Darwin

December 25, 2015	#33
Ricky Shaw Tomatovillian™ Join Date: Aug 2015 Location: Zone 6a Denver North Metro Posts: 1,910	T8's are are a good choice, higher lumen per watt and maintains light quality considerably longer than T12's If a gardener's doing just tomato and pepper seedlings, and the added heat of T5's is not beneficial in some way, there's really no need to look further than T-8's.

December 31, 2015	#34
loulac Tomatovillian™ Join Date: Feb 2013 Location: France Posts: 554	I enjoy following the discussions between experts on the field of lighting even if I really can’t add anything on the subject. I’d like to make myself useful : If Tvillian experts are interested in the opinions of French growers about lighting they can visit http://tomodori.com/forum/topic12592-45.html The thread was started in 2013, you can directly jump to 2015. If your French is bit rusty just PM me the date of the posts you are interested in and the name of the contributor. I’ll send you a translation and you will feel free to improve my English and may post your version on Tville.