Update LED lights vs T5 fluorescents experiment

[jhouse]

Hi all,

I had a thread awhile back, I switched to a Viparspectra light system for tomato & pepper seedlings because the T5's were very warm.

As it happened, I have so many seedlings that I placed some down cellar (where it's cooler) under the T5s, so I had a bit of an experiment going.

All the seedlings seem pretty happy, I've got them out under some sun/shade today, I plant late so I'm just starting to harden off. I planted my seeds indoors April 16 so they're just about 4 weeks old.

There is quite a difference, the fluorescent seedlings on the left are darker green, shorter thicker stems. (I did forget to turn the fan off once or twice so they got more fan time).
The LED plants on the right are lighter green and a little leggier, both have a little purpling the T5 plants were more purplish. I gave them all some Epsom salt 1Tb/gallon.
Will be interesting to see how they go once in the garden! (apologies for the styrofoam cups, using a more eco friendly option once I use them up)

[zendog]

Very interesting. How far up was the LED from the plants and how far up were the lights with the T5s? I would imagine that keeping the LED closer (and covering a smaller area of seedlings as a result I'm sure) would yield similar plants, but that is just a guess.

[jhouse]

The LEDs were pretty far from foliage, 32" or so. I spoke with their support guy at Viparspectra, a grower, and there's transitional period, but after that they suggest 32". I agree they seem to be reaching a bit. the lighting is on 70% foliage 30% bloom per their suggestion. I could try upping the lighting brightness or simply lowering the light.
Not sure the legginess will be too much of a problem, last time I grew from seeds I planted in a trench in the garden up to the first set of leaves, and had monster plants eventually.
My basil had a bit of reaction, not sure if burned a bit by lighting or irritated by the fan or just overwatered. They're okay -- I thinking sunlight will heal all!

[bower]

Both groups look great!

The bit more purple on the T5 group could just be that it's cooler at night when the lights are off.

[SQWIBB]

Go 24"
100% veg 70% bloom
16 hours on
Fan 16 hours on

[jhouse]

thanks SQWIBB, are you sure it won't burn them?

they got a couple hours of sun/shade and a breeze outside today --

thanks Bower, I've been fortunate for a somewhat beginner. i love this forum, that's where I got the idea for Fox Farm potting mix. Their people said there's good live stuff in there, so I've been using distilled water so my tap water (chlorine) doesn't kill anything.

[SQWIBB]

Seedlings were fine under my viparspectra 450's.
Actual wattage is 320 Watts with bloom and veg at 100%
I ran then with my bloom (red) at 70%. So I'm guessing about 280 Watts per light at 24" or less for 16 hours.
Start by upping the wattage one day then lower a few inches each day, you should be fine.

[SQWIBB]

A lot of advice giving for Led lights by the "experts" are usually geared towards cannabis growing.

[jhouse]

LOL yes I was getting that idea. ;-)