Pump Size?

I have a 16 x 32 inground pool starting at 3.5 ft and ending at 8ft. I need to change my pump and filter which is currently a hayward 1HP Super Pump and Hayward 244T Sand. The problem I have now is that when I replaced the liner 3 additional return lines were installed giving the pool 5 returns and 1 skimmer, all 1 1/2 plumbing and all individuall run. With my current pump, I am getting very low flow if any flow to the far returns should I upgrade pump size to 1 1/2 HP?

Welcome to the forum. You have about the same size pool as I and the exact same pump and filter. However, 5 returns? Just my gut feel tells me upping the pump size won't affect the flow at the far returns that much. With that size plumbing I think I would try and restrict the flow to the closer returns to try and equalize the flow before going to a higher volume pump. I also suspect the single skimmer will be the choke point in the system.
Al

Poconos is on target -- there's no need to up the flow, just because you've got a better set of lines. In fact, since you apparently still have only one suction return (your skimmer) trying to increase the flow could cause problems. A 1 HP pump is PLENTY to connect to a single skimmer!

PoolDoc