I've finalized my order for my pool kit and am very excited. 18x36 RH Kidney (20000Gallons), 27mil vinyl liner, Hayward Tristar 1HP 2speed pump, Hayward SwimClear 325 cartridge filter, ProLogic Automation with 40K Gal Salt Cell and Raypak 117K btu heat pump. My question comes while I think about connecting the equipment. I'm buying the full kit from PoolSuppliesCanada, who have been extremely professional and helpful in the whole process. They supply 1.5" hose and 1.5" fittings (elbows, couplings, ball valves, ect...) for the plumbing. I notice that all the equipment has 2" connections. I asked them about this and they simply said they recommend using the 1.5" and just step down from the 2" connections where necessary. I'd like to get other opinions on this... I was thinking of going with 2" connections, including valves and check valve, ect. between all my equipment (from pump to filter to heater to salt cell)...and simply stepping down to 1.5" to connect to the piping coming and going from the skimmer, returns, ect. Do you think this would be a complete waste of money, or would I benefit from less friction loss and higher flow where I need it most? I'm ready to purchase my package and would like to order all my fittings and valves the proper size so I don't have to worry about changing them in May when it comes time for the pool build.
Experienced advice is very appreciated!