Ok so,. I picked up a 75 tank "reef ready". It has 2 holes,. one 3/4" - one 1-1/2". It looks like to me it was setup with the larger hole being the return and the smaller being the drain. I am fairly new to drilled tanks (oddly enough I have always done external overflow for years.).
Seems to me like the drain should be the larger hole and the return the smaller one. Am I wrong? Please explain either way. Thank you!!!
Seems to me like the drain should be the larger hole and the return the smaller one. Am I wrong? Please explain either way. Thank you!!!