Nice DIY tutorial. A little rep for you...

I'm just about to start a new batch as soon as I get a little floor space for the container.
Mine is a lot like yours, but I seemed to have forgotten a spot to check the water level. I'm sure I can add one with little effort.

I just wanted to add to your tutorial here... You might want to consider adding a roll of duct tape to the list, to wrap the box after it is complete. My rubbermaid container let in a little light before I added a solid three layers of duct tape. Now she's pitch black on the inside. Anyways, not sure if you're having that problem, but I thought I'd mention it.

Anyways, good luck using it to grow, and I'll be looking out for a grow log Good luck!