Does my PVC sizes sound ok?

[dreamcatcherr9]

280g ish tank (72x36x24).

EMS 32” external overflow (3 - 1.5” drains).
Running down to sump using 1.5” PVC.

2 Varios 8 (1.25” outlet).
Running up to display using 1.25” PVC.
Dropping down to 1” PVC before tank / return.

Does that sound ok?

And how far or close to outlet nozzle at tank should I drop down to 1”?

Calculating how much of each size I’ll need. Thank you!

 

[slojim]

You can find headloss calculators to help you get a solid answer, but yes, those sizes seem ok

 

[ca1ore]

Drop down so as to run the absolute minimum amount of 1” pipe. I do similar on my tank. 1.5” flex up from the basement with 1” for the final foot.