[ApexLogic] had some PMMA core acrylic rod rod left over from a project and decided to use it as the lighting element in a laminar flow water jet.
The typical water jet consists of a bunch of sponges and drinking straws sandwiched together to slow a rough water stream and then a finely cut nozzle to provide a smooth ripple-free strand of clear water. If light is applied to this stream of water it tends to act similarly to fiber optics. [ApexLogic], however, uses a combination of shaved PVC filings, Brillo, and what appears to be most of the plumbing aisle of a local hardware store to get the same laminar flow. To top it off the polished acrylic rod is much less fragile than its glass-fiber counterpart and can have a high power light glued to the end for a nice water tight seal.
The system currently runs off of garden hose pressure, and would probably need some kind of a boost before it went into that front yard mega fountain that [Caleb] is still waiting for somebody to make. If you still need some clarity on laminar water jets check out these videos on a few