Punkduck was nice enough to send me his bathroom (http://www.makehumancommunity.org/forum/viewtopic.php?f=2&t=13672&start=210).
Question was: How to create convincing water jets emtted by the shower. The answer turned out to be easier than I initially thought. Just an array of small cylinders and a glass shader with a color of maximum white. I added some steam using smoke simulation.