Need overflow box help!

Ok, so yesterday I got the 210 up and going. Everything was working as it should, tested plumbing and powerloss conditions, no issues.



Today, I unplug everything to mount some power strips, set everything back up and the overflow lost siphon..... Now, it flows so fast into the sump that it drains the front half of the overflow to the point that when power is lost, it is unable to retain siphon. The only thing I've been able to do to slow the flow is roll up filter media and stick it in the stand pipes to slow the flow. I know this is not the way to do it, since the media can/will plug up or get sucked into the overflow drain hoses. Would adding ball valves to the drains help? Or should I be looking at a different overflow box? I am using a marineland S.O.S. over flow box. No place to attach an aqualift pump. Drains are 1 inch ID, hoses are 1 inch ID. Running a mag 9.5 return pump with a 3/4 inch hose up to a 1/2 inch pvc spray bar.



Any help would be great, I've tried to do some research but haven't had a lot of luck identifiying the problem....

 

Thanks guys, but at this point tearing the entire tank down and starting over isn't at the top of my options list. After talking to a.c.&c. and looking around online i am going to scrap the marineland overflow and go with a different style that will allow the use of an aquarium lifter pump.