Rob Meixner has a very nice setup. I think that I need to re-think how my (much smaller) setup is configured.
Mine was a plastic jug hung above the wheel, 1/4”tubing inserted, with a plumbing turn off to adjust flow. Works great!
Yup, just be sure to drill the hole in the bottle cap somewhat smaller to make a tight seal around the tubing. Cut the end you are putting into the hole to a tapered point so it is easier to get into the slightly smaller hole, then pull it thru as needed.
Mine takes a different approach. I have a CabKing 6-wheel lapidary grinder for which the water supply to the 80-grit wheel is always too scant. (FYI, CabKings have a top-of-the-wheel fresh-water supply; soiled water is drained away.) I use an aquarium pump in a bucket on the floor with tubing up to the housing near the 80-grit wheel. Attach the tubing in any way that suits you. (Duct tape suits me.) Use a clamp to control water flow. Tubing is available at pet stores that carry fish, or at garden shops that supply ornamental ponds.
“The arc of the moral universe is long, but it bends toward justice.”