Gardadore wrote: ↑Sun Apr 11, 2021 1:51 pm I use Promix as well but add extra Perlite when using it to start seeds. It makes it lighter. Coir is the base for my Earthboxes and Growbags.

For me, here, using coir instead of peat would cause issues late in the season when it gets cool and plants don't use water as much. Same with any mix that contains hydrogel for retaining moisture in the soil. I used that one season for container grown flowers and had trouble keeping them over winter in the cool garage.

I just wanted to add and say that I've grown Tomatoes under LED shop lights all winter in my basement. I wouldn't stress too much over UV. Yes it helps, but I've found that air flow has a higher impact.

Even my temperature was low. Around 65F. But my humidity was very low too.

Just wanted to mention that. There is a good possibility for success!

its nice to se this post some of my seedlings are doing the same darn thing!! some of then have leaves turned up and some have bumps on the leaves as well I just repotted all mine in plastic cups yesterday.. I didnt think they were growing much.. as far as lights go I have led shop lights. all new lights this year wanted to see if there was a difference in light from my other grow lights..glad I can learn from all these post.

The first time I saw ( or finally recognized) this problem was the year I got LED shop lights from Costco. I did some serious damage by moving my tomato seedlings under the shop light immediately after potting up and (generously) watering them in.
I didn't know at the time, the big difference between fluorescents and LED's. Fluorescents have a spectrum that includes more than one frequency of light, but the LED's are a single frequency ie a very narrow band light. The dedicated grow light LEDs do compensate for that by combining multiple LEDs to represent different parts of the normal spectrum. Many of them do still leave out parts of the spectrum that 'plants don't use'.
I would like to see a really good LED simulation of the whole spectrum of natural sunlight. I bet that would be best - not only for plants but for our eyes.

I'm glad that you posted this info Bower. I wondered what had happened when I moved my seedlings from shop lights to LED's. The LED's burned the leaves, and not just those at the tops of the plants, but most of the leaves. Thinking it was because the lights were too low, I raised them up, but made the same mistake again later and burned lots of leaves when I moved plants from under some strip lights to the LED's. At least it didn't bother some seedlings I had started on the windowsill.

I'm finding it very tricky using LED's because they are not very forgiving!

Linda

[mention]Labradors[/mention] I find that some things are very tolerant of the LED - greens and various Asian vegetables do fine. The strange thing is that red leaved varieties will often stay green under them, and don't show their true colors until they see sunlight.
I've always hung my lights in a window to try and get a little bit of daylight plus the supplementary light. Haven't tried that with LEDs though. The plan was to expand veggie terrain into dark corners, but sadly that will only work for lettuce and cabbage.
I had the same problem with peppers, which I was keeping away from the window to stay warmer, and under fluorescents. I had no idea what the edema was and thought they were insect eggs or some kind of infestation. Countless leaves trashed before the LED's gave me a wakeup call.

The plus side of the LEDs for me, which doesn't make up for the edema and other issues that frustrate me, is that I find mine are bright enough that I really don't have to harden my plants off much at all. I basically can take them from under the lights and put them outside without seeing any sunburn on the leaves as long as I pick an overcast day to move them out on or just move them out in the early afternoon the first day to reduce the change just a little.