I am jumping in to the deep end of this forum. I have an 18x43x28 L shaped pool that I am waiting on the county to issue a permit for so I can start the install. Whilst waiting I have a question on return location and sizing. I have attached a basic drawing on the pool and proposed locations for the 3 return's that came with the kit, but I have no problem adding a 4th.
My pump is a 1.5 horse Hayward with 1.5" connections
The filter is a Hayward C1200 with 1.5" connections
The pump and filter are 22' from the edge of the pool and there are 2 skimmers that are going to be plumbed together as one suction line and 2 mains also plumb together as one suction line. So there are two suction lines with a three way valve right before the pump which at this point are going to be 2" lines.
The return line can be 2" or 1.5" which ever is best and split as needed to equalize the flow to each port.
I know I am missing something to help determine this, but it is a beginning.