This Instructable is an improvement on a prototype like design that I submitted some time ago. See Semi-Automatic Hydroponic Planter/Sprout Grower. There were some inherent "problems" that I believe to have solved in one way or another. The biggest of which was access to the sprouts. This design has a completely removable grow chamber tub for easy filling/dumping/cleaning.
Having run for some time and not getting sick in the least after eating many harvests, I am satisfied that "I" will not succumb to any potential pathogens able to resist the frequent rinsing with chlorinated water. I'm still more worried about the door knob in any office building or coffee shop than "my" bathroom air. I can speak for no one else. I'm also more worried about the store bought, slimy, sulfur smelling, growth stunted sprouts/salads that come "fresh" in a bag.
If that still worries you, this unit could be placed in series with a drip as well. Anywhere, in fact, where there is a sufficient supply of safe water. A leaky tap (which should actually be fixed ya know), rain water, a stream or drip of any kind that can be fed into the top of the unit and supply coverage.
That being said, the new design incorporates a different and more convenient access grow chamber as well as superior, wall mount bracing. You're on your own if it's pretty you're looking for.
Step 1: What You Need
1 ea 2L pop/soda bottle
1 ea 4 inch dia. margarine or yogurt container w/lid
1 ea toilet tank...rest of the toilet optional...
Flexible tubing as req'd to interface with the tank hardware and create a sprinker/shower head inside the "grow chamber". Because I had a variety of tubing, I was able to something up using the following..... 2 ft of 3/8" OD vinyl tubing
4 inches of 1/4" ID x 3/8" OD polyethylene tubing (it's stiff and it melts to itself)
1 inch of 7/16" OD vinyl tubing (cut into 4 O-rings to act as ring clamps)
2 inches of 7/16 " OD vinyl tubing (coupler)
1/16" and 5/16" Drill bits
Pliers to bend coat hanger as req'd by mere mortals (2 pair)
Side Cutters to cut tubing
The need to flush at least twice a day doesn't hurt either. Actually, it's essential.