IGS does have a four shelf unit. Both the 3 and 4 shelf units are 72" high, which gives you less space between shelves on the 4-shelf unit. The advice I was given is that the 4-shelf would not give me enough space between shelves for standard violets. For minatures, the space would be enough.

The main thing I see with these greenhouses is the plastic doesn't come right to the ground so cold air can just swoosh up inside. They also tip easily outside. If you want to use lights you'd have to measure the length and get ordinary fluorescent shop lights. A 2 bulb fixture with fins on the sides to concentrate the light down is all you'd need. Of course you'd need one for each shelf. I'd figure out some way to close in the bottom to retain the heat at night. A 100 watt bulb clipped to the bottom shelf will throw enough heat to protect your plant from freezing at night but only if it's made air tight on the bottom ericsmith --take a look at the "pop up cold frame". You can set it up outside in a few minutes in the spring and it folds right up and into it's own small bag when you don't need it anymore. I bought one last year and I love it. It comes with stakes and has a skirt on the bottom to keep the cold and critters out

I have been running the Sunpark/Home Depot bargain shop lights ($8.99 each) along with the "better" quality ($14.99?) shop light with a improved reflector for nearly a year now without a failure, all in an overdriven configuration (One ballast per T-8 Tube). I purchased the needed additional Sunpark ballasts directly from Sunpark in Ca for around 6.00 per. To use a Sylvania or GE 4 x 48 T-8 electronic ballast from local sources ends up costing me a little more than double for one dual tube fixture than what I can make 2 for with the Sunpark ballast. I am also running them all through surge suppressors after the timer. Of note, the most recent purchase of this same bargain shop light from my Home Depot resulted in a surprise. The box and brand is exactly the same, but it is for T-12 tubes only. They do still have an electronic ballast, though it is a model for T-12 tubes. The "better" quality shop light has the T-8 & T-12 option, and is using what turned out to be a re-badged Sunpark SL-15T ballast. The new ballast in the bargain light fixture is the equivalent electronic ballast from Sunpark for T-12 lights with a different badge. I talked to Sunpark and they confirmed that they for now were the supplier of these ballasts, but would no longer be selling to this maker of fixtures. As I mentioned in another post, I did have a ballast failure recently while testing a newly wired up ODNO T-8 lamp, but there is a small chance it was not a ballast fault. No fire though it did produce some nasty & likely toxic brown smoke.

Lighting placement depends on the interior dimensions of the cabinet and type of shelves (i.e., glass vs. wood). For example, a display cabinet in the kitchen has solid shelves and is wider so led tape lighting was run up the sides, close to the cabinet front, and then across the top to meet in the middle and then exit up from there. For narrower display cabinets in the den, tape was just run up the sides. Short, wider upper cabinets in the dining room have glass shelves and mirrored sides and back. For those, led tape was just run across the top, near the cabinet front. A piece of matching batten molding was installed in front of the light tape to hide it when viewed from the front. Display cabinets in a sitting room are lit by led light fixtures installed at the top. In that situation, it was too difficult to hard wire them to a light switch. There is a switch on the light fixture and the cord is snaked behind the cabinet and plugged in behind a sofa.