I am going to build a three tier water feature with a 2' LED lit water fall in the middle and on each side a 1' LED lit water fall. I beleive that making with masonry block and then facing ot with a faux stone will be the simplelist approach. All three water falls together are rated at 4000 gallons per hour or about 66 GPM, so I am debating on running 2 1/2'' lines then or stepping up to 3''? Any suggestions? But my real question is how do I install the plumbing so that I dont have the supply lines freeze in the winter? While I am asking that question I am also installing my supply and return lines to the pool this weekend, do I need to slope these lines toward the pool so when I drain the pool below the skimmer in the winter they will drain into the pool? Want to only do this once.