I have a 55 gallon reef tank made of glass and i want to set up a sump below my tank. What is the best way to get the water from the tank to the sump and then back to the tank. Obviously pumps would work but I am nervous if one pump were to malfunction or not be in perfect sink with the other it would drain one tank and flood the other. Any input would be greatly appreciated. Also how big would you make the refugium/sump?