LED Replacement for 4' T5HO Fluorescent (F54T5HO)

[svalli]

This is very interesting discussion. I have also been looking, if there is a way to replace the fluorescent tubes with LEDs for starting tomato seedlings. Some tomato varieties have had intumescence problems when grown under LED fixtures, so I have used just regular cool white fluorescent tubes for tomato seedlings. I built new grow lights last spring using 6500K cool white and 25% blue/75% red LED strips, but some of those are now used for indoor flowers, so I was looking to get more lights.

I found in a FB group about LED tubes, which supposed to be 14000K and have a spectrum developed for growing seedlings.
https://surya-leds.com/en/veg-series/
I have read that high dose of blue may prevent that intumescence problem, so I got couple of the 13W tubes, which fit perfectly to my 90cm wide shelves.

Currently I have only peppers, flowers and some micro tomatoes started and I will be testing the new tubes with those. When I have more plants i will still need to use my old LED lights and also the fluorescent tubes to light more shelves.

So far it looks promising. I used a free lux app in my phone to compare the light between my led strip light and these tubes and the tubes give more light for the electric power. The app is not calibrated, so it cannot be used for real measurements, but it is OK for comparison.

LED lights.jpg

With my self made fixtures I had about 66W/ shelf and with the two tubes it is 26W. My strip light fixtures generated also a lot of heat, the aluminum plates are almost hot to touch when the lights are on for 15 h / day. One more nice thing about these tubes compared to my own builds is that the tubes plug directly to 230Vac, my own lights need separate 12 or 24Vdc power supplies.


Sari

[JRinPA]

I just checked the output with a cheapo Lux meter I borrowed, I don't know how accurate it is, but it is good for comparisons.

The LED's were actually about 50% brighter than the fluorescents...the fluorescents have one season on them, so maybe 1500 hours, maybe a little more, so they may have come down in output a little, I'm not sure I've looked at a T5HO curve, the T8's are pretty flat. It could also be the light spectrum that the meter is looking at.

But taken at face value, 150% of the light for 47.5% of the watts sounds pretty good, we'll see if I wind up with 1/2" diameter seedlings


PS Slugworth, I wasn't trying to do that...well...whatever that reaction to your post is that I accidentally clicked while trying to find the emoticon thing for my post.

Was yours a 4 bulb? Did you pay that $32.50 per led bulb? Have you tested it on seedlings in the last 3 weeks?
I'm still using my first grow light, a 4 bulb T5HO. It has 5 or 6 seasons on it. The inner pair are dimmer than the outer pair, and the inner pair gets even dimmer with air blowing over the seeds. So I've been thinking to change something.

[Setec Astronomy]

Was yours a 4 bulb? Did you pay that $32.50 per led bulb? Have you tested it on seedlings in the last 3 weeks?

Yes, yes, and no.

[JRinPA]

I think I paid around $80 for light originally. Maybe I'd go two LED bulbs (the inner pair that dims with air across them) and bypass that ballast. I do wonder how much the bulbs have dimmed over the years. Last year I didn't use it much and tried outdoor seed starting with only fair results, so I'm back to the lights this year. I've never really had a problem with this fixture with sometimes 8 1020s arrayed underneath it, except that it gives off a lot of heat and it is hard to start seedlings that want cooler temps.

I hope to hear some good results from your 4 bulb changeover.

[swordy]

Hello, I have a question here that may have been answered in a different way, but I will ask specifically for my case. I plan to build a grow lights plant nursery as a hobby (not professional), so I don't care for the ideal conditions. My goal is just a boost to the plant growth so seedlings will be big and strong enough to planted on ground in 2 months from now.
I have bought 4 led lights (6w each). They are white light, slightly with the warm effect. I additionally bought an old technology incandescent lamp 30w mostly for heat. I thought thay combing these two technologies I would have enough light, warmth and low consumption in watt. Is that correct? Do you suggest something else? Thank you in advance.

[rossomendblot]

It depends how much area you want to cover. 4 x 6W lights (are these bulbs or tubes?) isn't going to cover much more than a square foot or so. If you are looking to cover a larger area I would opt for some long, LED tube 'shop' style lights in a hanging fixture.

[swordy]

It depends how much area you want to cover. 4 x 6W lights (are these bulbs or tubes?) isn't going to cover much more than a square foot or so. If you are looking to cover a larger area I would opt for some long, LED tube 'shop' style lights in a hanging fixture.

Regarding your question: they're bulbs (led spot mr16 type)
And yes, it's just a seed tray 4x9 pots, (if I'm not mistaken, 1 square feet as you said).
My question is if this type of light(the combination I explain above) is ok for growing tomato plants. Thank you

[rossomendblot]

If the light intensity is high enough, yes, you can quite successfully grow young tomato plants with household bulbs. White with some warmth sounds like a colour temperature of 3500K or so. Since the bulbs are quite low wattage the total light output won't be very high, so you will probably have to keep the bulbs quite close to the plant canopy. If you notice the plants getting leggy and stretching, you will know the light is not strong enough.

[zeedman]

Just my 2 c's... if looking for seed starting lights & thinking about shop lights, don't overlook high bay LED fixtures. They can be very bright, and cover a large area. I presently use 6-bulb T8 high bay fixtures, but might switch over to LED once I run out of bulbs (if I'm even still gardening then).

[swordy]

After 2 weeks of 12 hours a day under grow lights I saw a huge difference in growth and development of leaves and thick stem. Yesterday I transplanted some plants from the jungle of the seedbed. As for the grow lights I used, I chose by chance some low watt led spot lights. I measured under the bulbs the intensity of light and even if it was not the same in every part it exceeded the expectations in some parts or was a bit lower than ideal in other parts

https://ibb.co/ySGHJ8P