hey guys my pool has 2hp haywood pump it has a chart in the manual regarding flow rates according to pipe size, now i hav 2 inch pipe to the pump, out the pump converts down to 1 1//2 pipe entering the filter and back out and thru my swg converting back to 2 inch pipe for return to pool. my question is what pipe size on the flow chart should i go by 2in or 1 1/2 inch.