As you know I have bought a few inexpensive shoplights to use for growing seedlings under. the shoplights run about $12 each then about another $8 for two bulbs for each fixture. So about $20 per light. To cover the area of a 72 cell seed tray turned sideways it take a min of 2 lights hung side-by-side. Then you still have a couple of inches of the edge of the tray outside the edge of the light, causing these edge seedings to lean a little in towards the light.My 3ft wide shelving unit only holds 2 trays end to end. However , if I hung 3 lights side by side, I could turn the trays sideways and get in 3 trays per shelf. Three lights would cost $60 to set up.
After doing some research on you tube, {especially this one:
Reaganite71} I found a way to set the whole 3 tray shelf up for about $9, plus the cost of 4 cheap extension cords for $1.37 each. Thats a WHOLE lot cheaper. I could only find 60 watt bulbs in my Walmart, 75 watt would be better probably.
Here's how it looks on my shelf:
I have a single shoplight on the top shelf for my narrow window box seed tray and some i have in egg trays. the second shelf has 2 shoplights hung side by side. The 3rd shelf shows the box light from the side view.
This is what it looks like from underneath.
This shows the box light hung in my shelving unit. You are looking up under it slightly to show the bulbs. With the foil, it seems pretty bright under here, and i can raise and lower the box over the seed trays to keep the lights close as possible to the seedlings.
Materials list:
4 Plug in adapters to screw the bulbs into.......... .97 cents each
Package of 4 spiral flourescent light bulbs these were about $1.88 for single, or about $5 for 4 pack, daylight bulbs. 60 watts each.{ 14 actual watts used.}Great Value brand
Aluminum foil
4 cheap extension cords about $1.37 each
Bottle of white school glue
Duct tape
Clear 2" wide packing tape
Large cardboard box
My box wasnt quite long enough. i needed about 31.5" long by the length of a seed tray (approx 21")
So I opened up the 4 corners of my box by cutting down each corner after cutting off the top flaps. I layed the one short edge down so I could make my box about 31" long. I used the flaps i cut off to add cardboard where needed to form an open box with the corners cut that was 31" long. My box was about 10" high. tape up pieces as needed with duct tape to hold together. I already had the tape, glue and foil, so didnt add these into the costs.
Now cut 4 triangles out of cardboard, the height of your box. You will spread the long sides out an an angle to give your box the extra width needed to allow a 21" 72 cell pack seed tray between. My box was about 6" too narrow, so my triangles measured 3" each on the wide edge, 10" high, and down to about 3/8" at the point.
Using duct tape, tape these triangle into each corner so the 3" ( or your desired width) edge is along the top (open side ) of box, and the point goes into the bottom of the corner made by spreading long sides out to make opening of box wider.
The above shot shows some white glue drizzled over the bottom to glue the foil down.
I started covering the bottom of the box with foil over the glue. Cut pieces so they extend up each side about 1". It took me two pieces side by side. Spread some glue where they overlap to hold in place and smooth everything down. Oh by the way, cutting aluminum foil with your scissors is supposed to SHARPEN them.
Here, I have 3 of the sides down, and now working on the short edge. I made the foil long enough to wrap over the top edge about 2" to the outer side of box. After folding it over stretch a piece of clear packing tape along the edge. You could also use duct tape if you like, but I thought clear tape looked a little neater.
When the entire inside of your box is covered, then I also taped along the edge with clear packing tape, extending it over the top edge to the inside to protect the edges from tearing. Do this on all 4 sides.
Now using a tape measure ( or eyeball it) measure about 9" in from short edge, and about 4" in from long edge, this is where you will center up your plug in adapters.
I thought I could make do with 4 lights 60 watts each. You might like 6. i placed the adapeter on the backside of box and drew around it with a marker. then using a knife, i punched thru the center of the circle, and sliced to the edge of the circle, doing this around the area for the hole, making slits about 1/4" apart. Now shove the adaper thru from the inside, prongs first. wrap clear tape around the backside to hold in place. Be extra careful there is ABSOLUTELY NO foil anywhere near any metal parts of the adapter, such as prongs, or inside where bulb screws into.
After you install all adapters, plus in your extension cords into these on the back side. Hold onto adapter on the inside while plugging in cord to back.Now leave one end loose to plug into wall, plug the other ends into the back of your extension cord. So you have a cord plugged into adapter, then a cord plug from another adapter plugged into the back of this cord. So all are connected. Now you should be able to plug the loose cord end into the wall, and ALL 4 lights work.
This is not the cord i used. mine was a cheap 6 foot one for $1.37 You will plug the adapter into one side of the end on left, and the end from another cord into the other side of same end.
Now hear this tomatoes and peppers, "Start Growing!" . I've got room for ya!
3/20/13 Update on tomatoes started under the new grow light:
These were started 3/9/13. So just 11 days later, I have pretty good growth. The area under the light is nice and warm, and I noticed (on the upper left of photo) there is even some condensation inside. I continue to bottom water all my plants on my seed started. And out of almost 100 tomatoes, 30 cabbage, 20 broccoli, about 40 onions,and about 20 head lettuce, I havent lost one seedling. I think thats pretty good results. I just started about 5 watermelon plants today, and about a week ago i started about 30 peppers.