I am planning in installing new salt generator and new pump to my existing Pentair DE filter and Raypak gas heater. Currently I have a 1 ½ PVC pipes with 1 ½ copper coming out of the heater and from the original underground (Pool made in 1972). Since I am planning to run my Pentair 8 speed pump at a very low volume/speed most of the time, I was wondering when I cut and redesigned the plumbing, should I reuse re-use some of the fittings and valves? Or should replace all my valves and fittings for an all 2” new plumbing. (The 1 ½ copper coming out of the ground will do to its nature of being underground will not be changed). Money is not abundant but I truly do not want to a Mickey Mouse job just to save 200.00 dollars.