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I am trying to build my own cheap lighting for my greenhouse. I have found a couple LED tubes that would be perfect for the task, only they are supposed to be mounted on a lamp of some sort. They have two G13 plugs, one on each side of the tube. Since I'm very ignorant in electronics, how would I connect them to the power socket? I suppose I would have to buy a power plug and some wire, but that's as far as I go.

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  • \$\begingroup\$ You buy a suitable G13 lamp holder and wire that to the mains. It sounds as though you should consider professional help for this project. \$\endgroup\$ – Transistor Oct 5 '18 at 18:11
  • \$\begingroup\$ That would probably solve the problem, unfortunately I wasn't able to find one of the right size, they are all quite big, and they are also relatively expensive, I could just buy greenhouse lights at this point. I have found though G13 sockets, alas I have no idea on how to connect the wires since there are two of them. Also, I read around the Internet and found out about the need of a ballast, do I really need one? \$\endgroup\$ – Valfodr Oct 5 '18 at 18:30
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    \$\begingroup\$ This would do better on diy, the home improvement site. That said, if they are g13, and a g13 base doesn't work, then they aren't g13. Maybe a smaller size? \$\endgroup\$ – Passerby Oct 5 '18 at 21:28
  • \$\begingroup\$ The problem was that I couldn't find a G13 base and was trying to understand how to wire the sockets myself. I've since been able to find a compatible G13 lamp holder though, but am now considering LED strips. \$\endgroup\$ – Valfodr Oct 5 '18 at 22:13
  • \$\begingroup\$ Are you not in the US? G13 bases are a dollar a piece at a big box store like Home Depot. You cold solder on some wire as a pig tail connector. \$\endgroup\$ – Passerby Oct 5 '18 at 23:39
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I have found a couple LED tubes that would be perfect for the task,

I highly doubt some G13 tubes are "perfect for the task". Especially if it has a frosted tube that will block half the photons. A clear tube can block 10% of the photons.


There are two main criteria when it comes to grow light LEDs, photons per watt and spectrum.

Plants mostly like dark red (660 nm) and some dark blue (450 nm).

enter image description here

Warm white (2700K) has more red than cool white (5000K).
High CRI (90+) has more red than low CRI (70).

Many growers will go for the cooler white because they a higher luminous efficacy (lm/W). A quality 5000K LED may have 180 lm/W where a 2700K may have only 140 lm/W. Plants do not care about lumens, only the number of photons. A 2700K emits almost as many photons as the 5000K when the LED under the phosphor is the same LED in both light sources.

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2700K 97 CRI

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The plant on the left is growing under 5700K the one on the right 3000K. The one in the middle was planted about 1 week after the other two.

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For most photons per watt, I recommend the inexpensive Bridgelux EB Gen2 or the Samsung F-Series strips powered with a Mean Well HLG LED driver.

This is seven $7, 3000K Bridgelux BXEB-L0560Z-30E2000-C-B3 strips
Driven with a Mean Well HLG-240H-C1400B. You can find a DIY guide at LED Gardener. You do not need to mount the strips to an aluminum bar. I just screw down the strips at the ends to the aluminum frame. No heatsink was needed with the Bridgelux. The Samsung you just reduce the current a little bit until the temperature is below 50°c.

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  • \$\begingroup\$ Thanks for the detailed answer, I had made further research in the meantime. I were able to find a good lamp holder for the LED tube, but ran across LED strips and it looked like a much more practical solution already. Thanks for the suggestion anyway. Only I can't really make our from your answer whether you are recommending warm light or cool light. I was going to opt for natural light in the beginning. Check this out: en.wikipedia.org/wiki/Grow_light#LEDs_(Light_Emitting_Diodes) \$\endgroup\$ – Valfodr Oct 5 '18 at 22:01
  • \$\begingroup\$ It would seem that while red light has been shown to promote flowering and fruiting, blue light would seem to promote vegetative growth. Green light though has also been shown to be beneficial, making natural light the "best" option... ? I thought that while one may want to go for white warm light while fruiting and cool for growing, I couldn't go wrong going for natural light (somewhere in the middle). Again, this is all based on very little scientific knowledge on the matter and extrapolation from various sources, so I might be awfully wrong somewhere. \$\endgroup\$ – Valfodr Oct 5 '18 at 22:11
  • \$\begingroup\$ The question now is what temp. I should go for: warm (around 2700K) or natural (5000K), given that cool (6700K) seems to not fare well from your pictures. If I had to hazard a guess, in most LED professional greenhouse lighting there is a much smaller number or blue LEDs than there are red ones. I'm guessing that perhaps cool LEDs have too much blue light? With that being said, I guess the main argument I have found this far supporting natural over warm would be the beneficial effect of green light. hortsci.ashspublications.org/content/39/7/1617.full.pdf+html \$\endgroup\$ – Valfodr Oct 5 '18 at 22:20
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    \$\begingroup\$ This is all very interesting and detailed, but how does it answer the OP's question "How to connect a LED G13 Tube directly to a power socket"? \$\endgroup\$ – brhans Oct 6 '18 at 0:56
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    \$\begingroup\$ And you're almost certainly correct. My point is that you've answered a Gardening & Landscaping question, not an electronics one. It's a great answer - I just don't think it fits here... I'm tempted to go and ask a question about grow light spectrum over there so that this answer has an appropriate home ... ;) \$\endgroup\$ – brhans Oct 7 '18 at 13:12

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