I have an overflow box that has 21, 1/4''wide X 1'' tall tooth openings in it. giving me 5.25 square in. of opening. How much water can flow thru that size opening???
Using the following input parameters
Gallons per Hour = 1400 Drain and Overflow sizes are calculated as
Recommended minimum drain pipe diameter = 1.55 inches
Recommended minimum linear overflow size = 21 inches