Put an electric float valve in so the pump doesn't come on when there is no water. If this is a regular occurence, then you probably need a larger sump, or shorter pumping times.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2053587.m570.l1313.TR6.TRC2.A0.H0.Xpump+float+switch.TRS0&_nkw=pump+float+switch&_sacat=0


float switch, not valve.


yes restricting flow is bad for the pump.

replace valve with T piece, have pipe go back to sump, put valve on that pipe.

run 1/4, 1/2, whatever water back to sump.

As Yavimaya said it's also best to have a "tee" and a ball valve on the pump that you can divert water back into the sump through the "tee" and then you are not throttling and restricting the pump, just controlling the flow up to the fish tank with the ball valve and the excess water is diverted back into the sump.

A larger pump isn't a problem because it's not being restricted in anyway the water is flowing in 2 different directions and water flowing from the "tee" will help aerate the sump.

With the "tee" and a float switch you shouldn't have any problems.

Restricting a pond pump doesn't hurt it at all, in fact it will draw less power. But I agree, add a tee and direct additional flow back to the sump, have the ball valve on that pipe and control from there.

Gunna makes a more valid point though that needs to be addressed - you shouldn't run your sump dry in a few days so more to the point you need a larger sump.

Restricting a pond pump doesn't hurt it at all, in fact it will draw less power.

Not sure about it using less power Charlie.