LED lights vs LED lights
 

2 years ago I graduated from T12 fluorescent grow lights to the 2 foot LED
grow light from walmart that hurt my eyes when I look at them.
Last year I got the 4 foot LED grow light bulbs for some of my fixtures.
I used a mix of all 3 types,with good results.
This year 1 rack was a mix of the LED only and I noticed the plants would lean
towards the original hurt my eyes lights instead of the 4 footers.
I think it is safe to say all LED grow lights are not created equal.
I glued magnets to the backs of the 2 footers to stick them to the shelves but
they were a pain to have so many.Walmart did have a more expensive bulb last
year but I was trying to keep costs down.Maybe I would have been better off.
2 years ago I had to hit 5 different walmarts to get enough 2 footers.

Interesting stuff. I like the idea about the magnets on the back. I've done a DIY frame around my seedlings with some old wire grid cube shelves (about 14" square) cable-tied into a structure on the bottom and three sides, so top and front are still open. My 2' T5's are anchored by wires, but also the plugs run through the grids giving it a little stability. I'm hoping we can just continue to make it higher as the seedlings grow.

Which type of LED grow light did you get at Walmart? I just did a search and I only saw a pricy (to me) one.

--Ann

[url]https://www.walmart.com/ip/Hyper-Tough-24-Led-Linkable-Grow-Light/713072660[/url]

That one you can go right from under the grow light to outdoor sun without worry about sunscald

The 4 foot t8 I wasn't thrilled about.
[url]https://www.walmart.com/ip/Great-Value-LED-Light-Bulb-18W-32W-40W-Equivalent-T8-T12-Grow-Light-Replacement-Lamp-G13-Base-Non-dimmable-Plant-Light-48-inches-1-Pack/192095851[/url]

[QUOTE=slugworth;756786][url]https://www.walmart.com/ip/Hyper-Tough-24-Led-Linkable-Grow-Light/713072660[/url][/QUOTE]

Wow, that really is a good price. Thanks!

My T8 fluorescents are actually in the lighting section of walmart,not the gardening.
I use a mix of 5000k and 6500k in a 4 foot fixture 1 foot away from the seedlings
no change of distance until they start hitting.

[QUOTE=kilroyscarnival;756846]Wow, that really is a good price. Thanks![/QUOTE]
they say linkable,but they lied.
Their other regular led lights are,but not these.
You need 1 power cord for each.
But it does have a rocker switch on the cord.
I glue the rare earth magnets to the backs,the ones that bite.

After 3 years of experimenting, I have come to some conclusions related to artificial light for tomatoes:
1) The minimum light intensity at the tops of the plants to avoid legginess is about 3,000 lux. Of course, anything over that is better.
2) The optimal arrangement is if the light comes from all directions. That means commercial grow lighting panels are not ideal, as the light comes from above only.
3) Combining sorts of sources works better than just one type of source. Fluorescent tubes combined with LED bulbs and LED grow lights work well.
4) For each stage of the plant development you need different wave length combinations. At the beginning, LED or f. tube day light (6,500°K) is quite enough. Later, when they start developing flowers, adding LED red-blue grow light is very useful.
5) Luminescent tubes produce some UV light, so if they are used, the plants are less prone to sunscald when exposed to direct sunshine later. Not that they are resistant. Maybe some professional grow lighting panels produce it as well.


I haven't experimented with arc sources as they use too much power and produce too much heat. They might be the option for glasshouses, but I don't have one. If anybody is interested, I will publicize some photos of my lighting system. I am not rich, so I work with inexpensive equipment. The results are not bad.


Milan HP

Sure,go ahead and post some pictures, I'd love to see what is working for you!

My Lighting System
 

1) A view from the loggia.

2) LED grow lights - off.
3) Reflector and LED bulbs.

4) Fluorescent tube.


Milan HP

Pictures
 

Sorry, a mistake has crept in as we say in Czech.

Thanks for the pictures! It looks like your plants need more light,they are stretching for more light. I'm guessing that if you able to produce fruit on those plants that they would be smaller than normal just because of low light. Maybe I'm wrong, maybe someone else will chime in with more info.

I don't think they are stretching and if so, not extremely much. They look different from each other: the tall ones are indeterminate varieties Start and Nelinka. There are two dwarfs: Arctic Rose and Sophie's Choice, naturally they aren't as tall as the former. And I also have a determinate plant of Mongolian Karlik. That plant isn't in the pictures as it is on another window sill. MK is just 15 cm tall, but very broad. Yes, more light would definitely help, but the pictures are much darker than reality. In fact it's 3 - 4,000 lux.

As to smaller fruits, you are absolutely right. They have always had smaller fruits than the ones in the garden. I take it for granted. But size is not important to me. I grow them for a very early harvest and for keeping myself a bit busy in winter months. Actually, they are quite expensive to grow as it is.;)
Milan HP



P.S. I am sending pictures of them before they were transplanted taken on Dec 28. They don't look leggy to me.

Your plants don't look leggy. Stocky but quite large. You can gain considerably more light from the smaller led's if you remove the diffuser. The globe has a small amount of adhesive holding it to the base. I use a large pair of channel locks to pop the plastic off.

I'm guessing these are 60-100 watt bulbs in the 5500-6500 kelvin range. Daylight only, not warm or anything else. Extremely bright white light will prevent legginess.