running two return pumps two different tanks but one sump?

[Hellothere12]

Hello everyone trying to add another tank on to my 150 gallon. So I have a 40 gallon sump with one return pump and small pump in my refugium feeding my frag tank, the frag tank has a overflow on it. So I want to possibly do one of two things here drill my frag tank and let gravity feed my new tank I would like to setup since my frag tank is 60" off the ground my my new tank will be 50" at it's highest point. Or instead of drilling a half filled tank just say forget it and add another pump to my sump to feed the new tank? The new tank has a overflow so I'm not worrying about flooding and my sump is drilled so another reason I'm sure I won't be flooding my basement please let me know your thoughts.

 

[WVNed]

I run 4 pumps in mine for 3 tanks. As long as they fit and your sump can handle the drain back if the power goes out it's fine.

 

[scabbedwings616]

Have some check valves on there right after the pump itself. I did this for my tank and it has never over filled my tank. it Will also keep the tank running if one of the pumps stops working. I use this on my tank in case one pump decides to not work.