RS 350 G2 Max plumbing question

[DesertReefer51]

I'm setting up a recently received 350 G2 Max. I'm replacing the metric hard plumbing for 1". I plan to connect the Reef Run 5500 utilizing flexible line. The issue I'm having is with the supplied adapter for the pump. It states it is 5/8" / 1". If I utilize this adapter and 1" flexible line I'm still restricted to the 5/8" opening.

Am I supposed to cut off the 5/8" end of the adapter? The manual isn't helpful.

 

[Asm481]

I would think you are supposed to cut the end off seeing the odd groove above the barbs for the larger diameter. What does it look like from inside the threaded end. Full width or reduced?

 

[DesertReefer51]

It reduces. I was thinking the same but I'm surprised no one else has asked this question.

 

[OctaviusBrine]

I’d cut it off if you are planning on using the 1” line.