I added another seedling shelf rack this year and I needed additional Grow Lights. I like these 4 Ft wire shelf units that you can find at most home centers or online. I also like these shelf covers to block out the light and reflect onto my plants.
I recently found a very reasonably priced LED shop light fixture at my local Walmart that seems to be just what I needed to add the grow lights for my new seedling racks. With output of 10,000 lumens at 100 watts and 5000K color temperature they are just what I was looking for. And at $45.98 I could not pass up the deal.
I believe the Number 1 cause for spindly weak seedlings is not enough light intensity. I started almost 20 years ago using six 4 Ft T-12 florescent bulbs in shop light fixtures over each shelf. Controlled with a timer set for 16 hours each day. I hung my grow lights on chains so I could keep the fixtures very low and raise them as my plants grow.
I later switched to a lighting fixture that I found at my local Home Depot. It was a four bulb T-8 florescent shop light with 4 Phillips 32 watt T-8 6500 degree daylight bulbs at 2750 Lumens each for a total output of 11,000 Lumens. I have since replace the florescent bulbs with LED bulbs to save on my power costs and reduce heat. I now use all LED grow lights. This seems to be working well for starting seedlings that will be moved to my greenhouse or outdoors.
Don’t be misled by low cost or unrealistic images. Low priced lights are usually lower intensity and are just not powerful enough for growing healthy seedlings.
There are many LED Grow Light designs available and some can be quite expensive. Almost all LED’s come from China, Taiwan, or Korea and the prices for the raw components lately has increased significantly. Manufacturers have been lowering costs by making low powered and less effective cheaper products for the home market. Be Aware of the output, color temperature, power use and size. I recommend 10,000 lumen output for my lights but that will decrease with the distance to your plants adjusting as plants grow. Look for color temperature at 5000-6500K daylight bulbs for seedlings. Some lights have adjustable color.
There are High-pressure sodium (HPS) and Metal Halide (MH) grow lights that are very powerful and more expensive. They can be suspended higher for covering a larger area and for taller plants in commercial greenhouses. They use a lot more electric power that will add to your power cost and generate much more heat that may require additional cooling fans.
LED Grow Lights use less electric power and produce far less heat. Lately it has become more difficult to find reasonable priced additional LED Grow Lights or to replace lights that do eventually burn out. I prefer to use longer 4 Ft fixtures in my large shelf racks and 2 Ft fixtures in smaller seedling racks. I found that around 10,000 lumens per shelf works best and 5000-6500K color temperature for seedlings. Hanging fixtures by chain lets me adjust the height as my plants grow.