This was a pretty simple project. I used a Rio 1700 submersible pump (since its only being used to move water around the tank Im not really worried about Rio reliablity). Anyway, the Rio comes with a 3/4" threaded attachment which I connected to a 3/4" threaded to 1/2" slip fit elbow. This elbow connects to another elbow which feeds the 1/2" lines for the jets. The jets are attached to the undergravel plumbing using 45 deg elbows, and each jet was made by heating up a short piece of PVC with a heat gun and pinching one end with a pair of pliers. I found that I needed to pinch the jets closer to the pump closed more to get an even flow from all the jets. I orignaly got this idea from http://www.vatoelvis.com/ in the articles section. It should be a good way to keep debris off the bottom of the tank. http://www.vatoelvis.com/ specifies 3 jets per pump, I used 5 jets which means that the total pressure out of each jet will be less but how much force does it take to lift a piece of fish crap? I could see if I had a shark or something. Anyway, if I find that the pressure isnt great enough, I can always stack a second pump on top of the 1st and feed it into the same plumbing or just get a bigger pump.