New pump and plumbing

[Myka]

Yeah 3/4" is the usual return size.

If you can't fit a 1" elbow behind the tank then put the reducer bushing on the bottom side of the elbow instead and use 3/4" elbow going into 1" pipe.

[Humpty]

Ok. So I will keep the pipe as big as possible for as long as possible.
Thanks for all your advice. I really appreciate it!!