To build the base it is quite simple. Basically you just need to make the water level indicator. Mark the tub with pen or the head of a nail. Drill a hole with the 3/4" bit in the very bottom of the tub where we will insert the grommet and then the 90 degree elbow.

NOTE: double check (measure) your grommet to make sure the drill bit is the right size. Mine is a 3/4" bit but you want to make certain that yours doesn't leak, and sizes vary. If you have to choose a bit that's either a little too small, or a little too big, choose the smaller bit. Seems easy but its also an easy mistake to drill the wrong size hole and find yourself going back to Lowes to spend another 6 bucks to fix a screw up.

Drill the hole as close to the bottom of the tub as possible. It's important so that you can view your nutrient level as it drops. It is also how you will be emptying your nute solution out of this when you do water changes.

After drilling the hole, take the burrs off of the opening with the utility knife. Be gentle and don't enlarge the hole, just clean it up so that the grommet will fit snugly. Now install the grommet by applying a small amount of liquid soap on it and inserting in in the hole. It might take a few tries as it is a very tight fit, but you want it tight to prevent leaks.

Next install the elbow through the grommet. Again it will fit very tightly so use soap to lube it up prior to installing. Finally measure and cut a length of the clear vinyl tubing, approximately 5 inches long and install it on the elbow fitting.
MVP Reviewed by MVP on . Building a Rubbermaid Hydro Bubbler Unit - Cheap and Effective Okay gang, here is a quick instructional thread on how to build a home made bubbler. I have seen friends use store bought units that are similar (google for Emily??s Garden). If you wanna see the concept, check out Greg Green's book "The Cannabis Grow Bible" where this idea is discussed as well. Getting started - first the parts list: (1) 10-gallon Rubbermaid Roughneck storage bin (Lowes $5.50) (1) ½ inch I.D. clear vinyl flexible tubing, 12? length (Lowes $0.50) (1) ½ inch Rating: 5