MAG 18's

[Quinster]

I lost my instructions for my MAG 18's and their web site has poor instructions on it...what I want to know is what is their recommended size pipe for these pumps. I seem to remember either 1 1/4" or 1 1/2" for the outlet side. I know you can never oversize the inlet, but I can't remember the recomended outlet size right now they are going through 3/4" and I know that is really slowing the flow alot!!

Thanks for any help!