In article om,
wrote:
Hello,

My 1 1/2 HP Hayward Super Pump kicked the bucket, so I thought I'd
upgrade and get the 1 1/2 Hayward Northstar, not realizing that the
Northstar had 2 1/2" inlet/outlet fittings (vice 1 1/2" for the
superpump). Can I just use reducers to bring my 1 1/2" plumbing to 2
1/2", or is that unadvisable?

Take it back and get the right one.
(From the voice of experience.)

--
Rich Greenberg N Ft Myers, FL, USA richgr atsign panix.com + 1 239 543 1353
Eastern time. N6LRT I speak for myself & my dogs only. VM'er since CP-67
Canines:Val, Red, Shasta & Casey (RIP), Red & Zero, Siberians Owner:Chinook-L
Retired at the beach Asst Owner:Sibernet-L