Need help with sump design.

I hope I am posting this correctly. My first attempt. I just purchased a 24x24x12 drilled Deep Blue with a home made unfinished stand that still requires a finished top and door. I have never used or built a sump, other than built in biocube sumps, which don't really count. I went out and purchased a 20g high tank as a sump. I have not installed it yet. I thought of the idea of using one of my 29g biocubes as a sump. It happens to fit into the stand like a glove. I want to push the return to the limit with the highest reasonable flow rate while keeping the refugium flow rate reasonably low. That is part of why I thought of the biocube. I don't have much for options if I use the 20g high. Its either high flow with poor fuge utilization or low flow with poor return flow rate. People keep saying that's what flow pumps are for, but it's a rimless and I would like to prevent wires from overhanging on the tank and I'm not spending $300 for a vortech magnet pump. I do understand that it may be an inevitability, but I want to try. Also, I am a firm believer of more flow the better. I have been speaking to Dan at World of Fish and Jason at Petco Minnetonka. Both guys are fricking awesome and I have much respect for them. I mentioned the biocube idea to them and they both really liked the concept, but said it's just a matter of how. I have a few sloppy drawings of ideas written on paper, but my main idea is to increase the size of the sump to half the size of the tank. Use a Rio 3100 for main return in sump portion and the original biocube pump for pulling a portion of that water into the refugium and over flow back to the sump. The idea is to have four chambers for the sump and then a separate camber for refugium that has its own lower flow. I need a good solid design for the sump area. I'm looking for opinions and pros and cons of either 20g high or biocube. Ideas on biocube layouts as sump. Possible ways of adding a 2-5 gallon fresh water topoff reservoir possibly mounted inside the stand above the sump. I really look forward to the feedback and help!

 

a 20H is the way I would go, I would also sell the biocubes but that is just me. I would set it up by splitting the drain with the first going to the refuge on the far side, the second drain to the skimmer section in the middle, bubble trap and then return.

 

A few people mentioned possibly stacking a 10 on top of the 20.

 

I picked up a SCWD today. I would like to see how much flow I get from my 750gph on it. I know people are going to say it's not going to be enough flow without additional power heads. I still need to attach the adjustable flow head to the hose on the right. I'm thinking of upgrading to 900-1000gph return

 

Looks like the tank will hold approx. 30 gallons. The 750 return pump puts you at 25X turnover without head loss. You may be getting an actual 500gph flow rate on the pump after head loss or 16X. In my opinion that won't be enough flow since the flow will be very directional with those flex nozzles. I'm all about not having any wires. My tank is covered in wires and I hate it, but I love the ease of the AIO tank when it comes to nanos. A 1000gph may get you there flow wise but there will be more problems to deal with, such as the directional flow being too powerful or problems with your overflow. I'm not an expert on overflows by any means just giving my opinion. You could buy a Jaebo powerhead for now and slowly save up for the Vortec or scan the local reef forums for a used pump. You could always sale some frags in the future to help offset the cost.