1 or 2 Return Pumps

[Born7]

350 gallon aquarium. 2400gph. [4] 3/4" returns. I'm hard piping returns in 1" pvc. Reducing to 3/4" at the bulkhead. I'm thinking [2] Jebao DCP-8000. I can control flow.

 

[kno4te]

I’d say 2 for redundancy.

 

[DN328]

I think two is generally better for redundancy, but I'd imagine can be a pain for PVC. You likely have a lot room plumbing space for the 350 and can do some clean runs. I know it doesn't matter per se, but I like trying to run the PVC to make everything look clean and tidy.

Keep in mind the head pressure, and PVC elbows to achieve your desired 6x-7x turnover.