Need help with return plumbing

[rueric]

Hi folks,

I need some help as this is the first time I’m having to setup / deal with plumbing.

I bought a used reefer 350 and also a used cor20.
The plumbing on the cor20 needs a slightly bigger tube then the one that the reefer 350 uses.

based on the picture attached, what are my options?

it looks like the previous owner for the 350 created a Y split for perhaps easier water changes?

if I wanted to keep using this split, I would have to cut the PVC since it uses attachments for a jebao dcp8000

 

[Fish_Fry]

Red Sea uses metric sizes, this thread talks about what parts you need for the conversion.



https://www.reef2reef.com/threads/750-xxl-piping-size.657997/