A Word About Lighting
You may be wondering what we use for lighting. Presently, we use 4-foot T8 ballasts with half cool white and half bright white (fluorescent) 32W bulbs. This equates to approximately 13,000 lumens. We have six shelves, each shelf has the capacity for 2, 1020 trays and adjustable heights up to 2 feet per shelf. And, we are in the process of expanding our setup to include a third plant stand with three more shelves.
We keep lights on 24/7 once seedlings emerge to maximize vegetative growth, and simultaneously unplug the heat mats to cool the soil. Lighting seems expensive to me as we spend resources to keep these lights on, especially fluorescents. And yet, on the other hand, we know this system intimately and can't justify wasting these light fixtures and their bulbs; we will continue using them until they wear out. And, in the simplest terms, we have had really good success using a mix of cool and bright white fluorescent bulbs in our T8 shop lights, so I can't justify the added expense either. Perhaps by the time these bulbs wear out, there will be strong enough T8 LED replacements that will be comparable to our current output.
In the past few years we've had to start over with some of our lights. If memory serves me, we had T8 grow lights from a hydroponic store, but when I went to buy new bulbs they had discontinued them; we didn't feel like investing hundreds of dollars for a few T5 lights. LED was not available at that time at a price point that was approachable. So, we chose to switch to T8 fluorescent bulbs and selected the Lithonia T8 4' shop lights from The Home Depot. We then purchased 2 of each cool white and bright white bulbs and installed them every other in the fixture so the light spectrum is a broader range than just using one type of bulb. I bought 2 new lights and bulbs for about $150 last month. So, we currently have 5 T8 ballasts with fluorescents.
The other big question I get asked often from friends who start their plants indoors is why aren't ours leggy. And the answer is simple: with fluorescents, you must keep your plants as close to the fixture as you can because the light doesn't penetrate very far down. How close do you keep your light to your plants? If they are fluorescents like ours, keep the light as close to the plants as possible without touching. For these lights, the cage of the fixture is usually just about touching the plants. The light won't burn the plants, so don't worry about that, and bringing the light to them eliminates the plants' need to reach up for the light since this light is not as strong as T5s or high output grow lights. For us, at the end of the day, we are successful enough with this system to not justify the additional cost of the new fixtures and bulbs.
However, as our garden has expanded, so has our need for indoor growing space. We will be giving at least one shelf a test run with an 300W LED light. We are slow adopters with this technology, having heard mixed results of success with various starts. We have also heard from multiple sources that seedlings do better when germinated under fluorescents, and only moved to high output after having first set of true leaves.
I can't say in the future we won't transition solely to higher output LED lights, but for the foreseeable we will stick with our successful, affordable model.