Pentair recommends a straight piece of suction pipe that is 5x the diameter of the pipe size. So if the pipe is 2", then 10" is required and for 1.5", 7.5" is required. However, it is important to understand why they have that specification. I think it was mentioned before but this is to prevent a vortex in the water entering the pump basket. A vortex increases head loss which lowers the pressure near the impeller which in turn increases the possibility of cavitation but only under certain conditions. This usually only occurs at very high flow rates and depends on the head loss in the rest of the plumbing. At lower speeds, NPSHa increases substantially and the posibility of cavitation decreases dramatically so this is much less of an issue. However even at low speeds, a vortex will always reduce the efficiency of the pump some but it is not all that much. I'm not suggesting that you ignore the recommendations of Pentair but it is important to keep it in context. If you don't plan on operating the pump anywhere near full speed, the length of suction pipe becomes less important. However, looking at the photographs that you have, it looks like you could easily run a 10" straight pipe away from the pump close to the opposite wall. Run a 90 back along the wall to a header which connects all of the suction pipes after each valve. This has a few 90s in it but if you use 2" pipe, it is not that much of an impact. Also, 1-90 has about the same head loss as 2-45s so you really don't gain much by using 2-45s but you can do that if you want. The important part is to have the straight piece of pipe in front of the pump. The extra fittings and pipe are much less important. At 60 GPM, a 2" 90 has about 0.27 feet of head loss. 2-45s (2") have about 0.25 feet of head loss. Not much difference and not much in total when you consider most suction plumbing will be close to 5 feet of head. Also, the optimum flow rates for a filter are for the upper end. So you can always go with lower flow rates and still achieve optimum filtering. In addition, you will save much more in energy costs if you can target close to 1000 RPM with the Intelliflo.

Love the quotes. I have adjusted to many situations in my life, but I have also changed to conditions that are more favorable to me. Re the W. R. Inge quote. Water also carves out a path of it's own making.

Manipulation seems to be a constant in humans. I can relate to the Joseph Wambaugh quote about jury selection, I have been twice dropped from the jury after the question if I knew about the case. When I said I did, was asked how come. I told them I read the newspaper and listen to radio and TV news. I was sent home.

I agre with him in is opinion of Faulkner, I know he's one of the must read authors, I could not get through his verbiage nor relate to the troubled folk he told about in too many words.