Before I fill it with water....

[brewercm]

Do you think a pump driven drain and a pump driven return would work better in my setup than a gravity based drain and a pump based return?

I'd never recommend a pump driven drain. That would be almost impossible to get bot pumps working together exactly the way they are needing to. Second if one goes out or starts to slow down you will have a disaster.

A system should be designed on the fact that your drains are rated higher than your return pump. The system equals itself out then by using an overflow box that is set to have the water at a certain hight in the tank. You have a constant flow of water through your sump that is rated at whatever your pump is sending back.

Hope that makes since.

[LoneStar]

Do you think a pump driven drain and a pump driven return would work better in my setup than a gravity based drain and a pump based return?

I'd never recommend a pump driven drain. That would be almost impossible to get bot pumps working together exactly the way they are needing to. Second if one goes out or starts to slow down you will have a disaster.

A system should be designed on the fact that your drains are rated higher than your return pump. The system equals itself out then by using an overflow box that is set to have the water at a certain hight in the tank. You have a constant flow of water through your sump that is rated at whatever your pump is sending back.

Hope that makes since.

Physics will kill that idea, sorry (the pump driven idea that is). I agree with what brewercm said. You will get a constant flow if you have water pumping in and gravity flowing it out. Just make sure your drain can handle the flow from the return pump. If you pump in and then pump out, you will see that the 'pump in' pump has to push a lot harder and loses its gph flow, because of head height. The 'pump out' pump barely has to work to push the water out of the tank so it will be moving water at a different rate than its counterpart.

It would make a cool science experiment if you could equal both pumps out to their specific flow rates at different levels. ;)

[LoneStar]

You could pick up scrap acrylic fairly cheap and save money by making your own overflow box. Regal Plastics in town sells large scrap pieces for a $1 a pound, and it wouldn't take much to build one for your tank.

[hammondegge]

here ya go hobo http://www.melevsreef.com/sump.html
there is a weir style overflow diy on this page. other useful information on plumbing and sumps throughout the site. g'luck