How to control flow of sump and main tank?

[makko75]

I'm using a 10 gallon tank as a sump for a 46 gallon display reef tank. I'm using 3/4" (inside diameter) tubbing for both lines. I'm using the standard Custom Flow System and it comes with valves. I've been tweaking the flow since last night and I can't get the level of water to stabilize. Anyone have any ideas or is this something that I'll have to mess around with it until I get it right.

[Reefland]

You will never get the flow equalized without the use of an external overflow box. The external overflow box should be rated as close to your return pump as possible, without being less (in my opinion). So if you have an external overflow box that is rated at 600gph, and a pump that is rated at 550gph at 4' head, the water will equalize between the two on their own.

[makko75]

Problem solved. I found an old overflow box that corrected the problem. Thanks!