I want to drill return hoke(s) in my 75 g display tank. What size holes should I drill and how many? I have 2 return pumps to choose from Mag Drive 9.5 or Eheim 1262. The Mag Drive seams to be the stronger pump.
I guess that depends on what size plumbing you are using and which bulkheads you purchase? I would recommend 1" sch40 bulkhead. For that you would need a 1" bulkhead and drill 1 3/4 inches or 45 mm hole.
