I am getting ready to convert over to a salt system and need some advice on a change I have been thinking about. Every piece of equipment in the system has 2in connectors by default. In my case, every piece of equipment has a 1 1/2 bushing attached since everything coming and going to the pool is 1 1/2 in. I have had various suspicions that I am unable to push enough water out the pool and spa returns when the input to the pump is only an 1 1/2 in connection. Once i split the returns I am trying to push more water than is coming in. So my thought process was to use 2in from the top of the valves on the input side all the way through to the return split. The salt cell appears to be 2in by default too so that is why I am thinking of doing this now because why add another item in the mix and push it down to a smaller size. My issue is I'm not sure this will help and its only a theory in my head. Since it will cost me to replace all the adapters to each piece of equipment that has a bushing now glued I'd like some confidence in this decision before wasting my money and possibly making the situation worse.
In the picture below the two valves on the far left control the input from the wall port, skimmer, and main drain. The next valve inline to the right of those controls the pool input vs the spa input. The valve furthest to the right is the split on the pool and spa return. Not in this picture is the heater which is further to the right and installed after I took it.