So I am about to make a deposit on a custom rimless aquarium 66"L x25"W x 22"H the aquarium will be drilled for a 1800gph 18" modular marine overflow the builder asked me to draw drilling instructions out and take a picture I did but haven't sent the photo yet just wanted to see everyone's opinion on the instructions before I send it. Also plan to have a 1.25" hole drilled for a single return bulkhead do you think it's a good size return for this aquarium?