Pump too big

[bevancristi]

I had a guy in town build a sump and refugium for me. I have 3/4 lines coming in and out. From the tank to the sump. I have a Danner model 18 pump. 1800 GPH. Well the pump is pumping all the water out of my sump. What do I do? Do I go with a smaller pump or what?

 

[lilredwuck]

you could go smaller or get a ball valve to controll the amount leaving, or you can T off of it and have some go to the tank and some pumped back to the sump

 

[scsinet]

I'd downsize the pump.
There is only a certain amount of dialing back that is wise to do. After you dial back to a certain point, you're just burning electricity and potentially being hard on the pump.
A mag 18 is ridiculously oversized for a 3/4" drain line (or even two of them). I'd use a Mag 5 for this, and even with that, you'd need a ball valve in most cases.

 

[bevancristi]

What would be the ideal pump for 3/4 line? Would a over flow box on the aquarium be a idea? Thanks for the help