I'm still not feeling well, but I got most of this assembled last night before the fever came on. I'll go through my steps to make it without a lot of commentary.
aquarium air pump (20 gallon or larger)
2 bubble wands
black spray paint
silicone caulk for bath/kitchen
1. Paint the outside of the tub with a good spray paint. Krylon makes a brand called Fushion that is made for plastic. I had some Plasti-Dip, so I used that. You just need to keep light out of the rooting zone.
2. When dry, drill hole(s) for airline tubing. Attach bubble wands with silicone. Seal holes after inserting tubing.
3. After 12 hours, I turned the container on its side to glue the suction cup for the heater using the same silicone. 12 more hours for that to dry. Then I filled it with water and turned it all on.
4. In the meantime, I used a 3/4" hole saw bit from my doorknob installation kit to drill 77 holes on 1-1/2" centers in the top.
5. Once the temperature of the water reaches 78 degrees, you can stick your cuttings. I'm using a vinyl placemat cut into 1" squares right now. I'm not happy with the method so I'll try to find a better solution.
I also covered the top with another clear container. They allows me to let light in while providing a 100% humidity environment.
Now all we do is wait.
I plan to let it run a couple days before sticking any cuttings. I want the water temperature to be correct. I also need to find a better method of holding the cuttings in place. I'm considering communion cups. They're 3/4" in diameter at the bottom.
UPDATE: After all this, I decided to use a smaller tote. The lid fits a 7" tall tote I had laying around, so I painted it black, glued all the parts in place, and it's running now. Still waiting for the water to warm up. Anyone want to help move a tote full of water outside?