Sump on a nano ?

[Acipenser]

O.k. so I believe I have the problem solved - However I am unsure of the BEST solution. I believe that the return pump is under powered for the amount that the drains are flowing into the sump. I have 2 x 1/2" drain lines flowing into the sump, The Eheim return pump at full volume cannot keep up to dual 1/2" drains. I have fitted 2 ball valves into the drains to dial back the flow. I realize this is the wrong method but it was the cheapest and works to the point where I can adjust the drains to match what the Eheim can return. At this point after 12 hours the display tank level and sump stay the same.

The proper method would be for me to either add a second Eheim pump or 1 larger pump and have a diverted return line with a proper gate valve back into the sump.

Thoughts ?