Okay.

Take a look at this link.

Note the pulleys and winch used to raise/lower the lights.

Home Depot has a sale on their Commercial Electric shoplights.

Here is a link that might be useful: {{gwi:1022399}}

Paul,

"My initial plan is to build a three shelf unit that is 24" deep, 48" wide, and 6" tall."

My two lightstands have almost identical dimensions to yours. I am using two units of the Northern Tool chrome wire shelves. The shelves are 69 inches tall but the 5-inch wheels bring their height above the floor up to about 74 5/8". I moved my bottom shelf down to its lowest position just above the wheels.

All of the shelves are adjustable in one-inch increments. The open chrome wire design is handy for a number of reasons. The shelves are waterproof, don't hold water, and they are handy for hanging things from. I just hang my overdriven Home Depot 140-904 shoplights directly from the shelves and adjust their height with the chains. I got some 1-inch S-hooks to attach the chains with. I get four shoplights per shelf and since overdriven fixtures put out 50% more light, that is equivalent to 12 T8 bulbs per shelf. I get the bulbs in boxes of 10 for $19.99 from Home Depot, so that brings the bulb price down to $2 each.

Last year my onions got 18 inches tall, so I think the shelves could accommodate your tomatoes just fine. I also hang small electric fans on chains for air circulation on the plants. The artificial wind seems to do them good.

If you do decide to go this route, Northern Tool has free shipping on orders over $149 so you could buy something else from their wide selection to bring your order over that amount and the savings would make that extra thing essentially free.

MM

Hey, MM, thanks for the link. I just got off the phone with NT and they're kinda clueless.

I had searched their site for shelving. Picked a item number. (Turns out it was priced by the shelf, by the wire rack, etc.)

I asked about this item, and finally they came back with "that's not a shelf unit, that's a wire rack for a shelf unit".

So, I said "The picture shows an entire shelf rack. Is this the wrong picture then?"

Which is of course the answer. The picture didn't say, "this wire rack fits this shelf unit".

They didn't pick up the ball and point me to the link you provided even though I told them what I was looking for.

Maybe they should be paying you commissions !

At any rate, it looks like a good product.

Here's a plan for a nice, easy-to-build rack.

Here is a link that might be useful: Seed-starting rack

Here's one I've been developing/building for the past week or so.

Here is a link that might be useful: Homebuilt Light Stand

I built the stand that nygardener has the link to. I modified it a bit and made it 24 inches deep so I could use 2-double shop lights and four trays on each shelf.
I love this stand. It has served me quite well for several years.
Happy Gardening...................Tom

I guess I'm just lazier than most because I 'put together' a seed starting unit that has worked very well for a number of years. It is a Heavy duty angle-iron type shelf unit with particle board shelving. I put eye hooks in the underneath of one shelf to hang the shoplight chain from, giving light to the shelf below. It currently only has two shelves going because that is all I need right now but when I need the other shelf I can hang the lights in about 2 minutes. Cost of the Heavy Duty 4 shelf unit was about $40 on sale....6 shop lights at $5 each....a power strip to plug everything into and a timer that's starts and stops the lights automatically. Total cost was under $150 and that includes a heating mat. I also have velcro tabs on the shelves so I can hang plastic sheeting to make a green house effect. Since I have been using the APS self watering systems, I don't find the sheeting necessary. If I could figure a way to put a picture on here, I could show you but haven't figured that out.

Cherie if you have the pic stored somewhere online, I have been able to right click on the pic then left on properties and it will show the address for the picture. Copy this address, then on here type <....img ....src...='..."' pic address>
leave out all the periods.

Popepaul,
I built a shelf unit from Northern Tool with MM's help and I'm very pleased with it.. I was looking to purchase a shelf unit/cart from Harris Seed Co.. The self unit/cart I built saved me more than 1/2 the price and I gained 100% more light output than the Harris stand.
I personally would trust what MM's telling you. He didn't let me down through-out the whole buying of the cart and lights and setting up process. He was there to answer any question i had with-in hours . For that i eternally thankful. However, i may have let him down by not posting the pictures of my new shelf, and for that i apologize.
MM i will get to it I promise.. I have a lot on my plate I'll be in touch, and thanks for your help.
In my opinion, you couldn't find a better mentor to help build your stand.

Sincerely,
F