I have a pool that was made with 1 1/2 inch pipes. I really should have had 2" but it wasn't designed very well so that's what I have to work with. The pipes are in cement so there isn't much hope of fixing that. I am replacing the filter which is undersized with a swimclear 2030. I an trying to decide how much pipe I should replace with 2" pipe since that is what the 2030 takes. I can go direct from the pump to the filter with only 2". The output from the filter will be 2" but then it will need to go down to 1 1/2 at some point. If there is enough benefit I could rebuilt quite a bit and do 2" for several feet after the filter but that will mean that I have to buy a new flow switch and fittings for the SWG that is installed. Is there a problem with the filter having only 2" before the filter and some 1 1/2" after the filter? any input would be appreciated.