Thanks for the quick replies Sue and DNic. I have been comparing prices on system components. 3/8 weighted tubing is about 30 to 40 percent cheaper than 1/2 tubing. If there is no real decrease in performance at the distances I asked about then there would be quite a bit of savings in using the 3/8. DNic. I do plan to use common air line to the manifold but will still have three long supply lines to my diffusers. I am planning to do this project next spring and I am trying to find out the ballpark costs before I engage with salespeople. I appreciate the tip about the possible problems of having the pump below the water level behind the dam. I want a first rate system but I also want a competitive price so I am doing some research.
Tom Sterling (Shelby County)