From a different thread:
Quote Originally Posted by PoolDoc View Post
The WhisperFlo is almost certainly too big . . . unless you get at least a 24" sand filter.
I expect to throttle the pump and/or run the pump on low. I have a valve for that purpose ordered. The owners manual has flow/head curves that show the pump moves 45 GPM max and about 15 GPM @ 20' on low. High speed moves 95 GPM max, 85 GPM @ 30' and about 22 GPM (close to what I need) 80'.

Quote Originally Posted by PoolDoc View Post
Look at the differencee between these bulkhead fittings:

Hayward SP1023 bulkhead fitting
Hayward SP1023G bulkhead fitting

Please let me know which bulkhead you use, and it works.
The difference between SP1023 and SP1023G is the inclusion of a "sandwich washer" in addition to the standard washer with the -G. I think I'll be okay with the non-G fitting. If they leak, I'll order the sandwich washers (assuming I can) or return the non-G fittings and order G type.