I have found that the biggest challenge in sprouting seeds is that they NEED to see near SUNLIGHT LEVEL lighting from the minute they pop out of the medium, and for about a week thereafter. It is essential. While clones can be exposed to lower level light for weeks after rooting with no ill effects, seedlings in low light will stretch rapidly getting 2-3” tall with a thin spindly stem and ultimately fall over in just 1-2 days. You then have to prop them up for a week or more till the stem begins to thicken.
I like many people did not want to have to dedicate an HID fixture for seedlings, outdoor sun is hard to find in my yard, and the T5 fluorescents I use for my clone nursery are simply not bright enough.
So in cooperation with California LightWorks, I decided to try a CLF SolarFlare 220 for my recent round of 50 feminized seeds. My nursery is a 2’x4’ tent and one SF220 got me around 1000 mmoles / m2/s at 16 inches. That is the level I suspected was around the threshold for short, thick, healthy seedlings.
Early seedling development is mostly in the roots and stems, and red spectrum promotes roots and stems while blue promotes leaves, so I chose the CLW SF220 flower fixture instead of the veg unit, but I think either model will work very well.. (Also I happen to have extra 220’s flower units that I use as supplementation to the HPS’s in my flower room.)
As you can see the results were EXCELLENT. Short plants with thick healthy stems. Really nice. And I turned the lights on a schedule of 16/8 just as soon as the first seedling came up, so the lights being on while they were still beneath the surface had no ill effect.
For those of you who use seeds, I can say I highly recommend using this light for seedlings. I would leave them under the LED’s for at least 1 week after sprouting.
And remember, when you insert the seed, put the rounded side up, pointy side down, and wet your rock-wool cube, peat plug, etc.. with a good VEG / ROOTING nutrient solution around 700PPM.
SILAS TIP: If the initial tap root of both seedlings OR clones is air pruned at around 4″ down, it makes the root start branching very early and extensively. I use the 4″ 3×6 RootMaker Express propagation trays in these pics, for ALL my seedlings AND clones. I leave them in the 4″ until they are around 8″-12″ tall before I transplant and the root development is absolutely FANTASTIC. You have hundreds of separate little roots in just a 4″ pot instead of a few long ones circling around. You can literally move them straight from the 4″ RootMaker into a 5 gallon pot with results FAR SUPERIOR to vegging in a 1 gallon(ish) plastic pot or just putting the clone straight into the final 3-5+ gallon pot. But 4″ is the the magic length for the first root prune, so try it in the RootMaker express 4″ trays and see the amazing results! I use them for ALL my babies, both seedlings and clones.
To those who grow we salute you!