Hi All,
Planning out my sump for the 72g coast to coast overflow project based on Bean Animal's design. Here is what I have figured.

20g long sump
2 x 50 micron sock filters
3 gallons of bio-balls
700-900gph pump

The normal operating capacity should be about 15g leaving 5g to catch the extra water in the overflow which should be about 2g. What do you think? I am open to alternate designs