does a closed loop have to be closed?

[jh1929]

Is there any reason you can't just add another return pump from the sump and loop some pvc over the edge of the tank? The only advantage of drilling and making an actual "closed" loop that I see is the added current generated at the inlet.

Jayme

[golfish]

If your overflows and sump can handle the flow them by all means add another pump. My 40 gal sump can't handle 3000 gph without putting a bunch of bubbles in the tank and sounding like a waterfall.

[Randy V]

You can do what you describe but it's not a closed loop then, it's just an additional return pump.

The point of a closed loop is to provide additional circulation without that water having to flow through the sump. Increasing flow to the sump unnucessarily just adds potential bubble issues and increases the flow capacity requirements of the overflows. You will also get more current from a given pump since it doesn't have to overcome head resistance.

[Wazzel]

J

You do not have to drill to get a closed loop. Just run some pipe over the lip of you tank to a pump and back. Make sure you prime it the first time and any time you service the pump. Ther are a few good trheads with pics do a search.