Im just thinking ahead… who has an external refugeum set up? I have a 55gal display and a 10 gallon sump. Any ideas on setting up an external refugeum? Do you pump the water back and forth? Over flow? Thanks for any insight!
I'm not sure what you have in mind when you say external refugium. Usually internal refugium means its inside the display tank. Are you thinking about a hang on back refugium, in the sump, in addition to the sump, between the tank and sump?
Regardless, pumping water back and forth never works. Even if you get the pumps tuned perfectly, over time one will get clogged or slow down and overflow something.