Originally posted by kinkfish
overflow? isnt that supposed to be biult in ndwhat is in it how does it work?
No it doesn not have too be built in, you can buy hang on's. Overflow are too bring water from your tank, too bring them down too the filters, sumps, fuge's skimmers. Then the water come back up too the tank by a pump.
Here is a pic of my hang on overflow.
lucky - sorry for getting off-topic