I found the following useful, and thought I would share. I'm certain the values are estimations only, and, that there are other variables that affect actual flow rates. For example, the length of vertical pipe, and internal condition.
The images and information are from The Reef Aquarium - Volume Three - Delbeek & Sprung, and, Steve Jackson of Aquatic Eco-Systems Inc..
The images and information are from The Reef Aquarium - Volume Three - Delbeek & Sprung, and, Steve Jackson of Aquatic Eco-Systems Inc..