Will This Work?: Intank overflow

I'm migrating my 20 gallon tall over to a 40 gallon breeder and was going to utilize another 10 gallon to be my sump. Plans changed and now I won't be able to do so. So I thought I could partition 10 gallons of the 40 out to make a nice area for a refugium (~5 gal) and a Cheato grow out area. So I came up with the idea below. The first picture shows block diagrams of where everything will be located. I calculated a 275 gph through the overflow with my pump being 300 max. I plan on using a valve to throttle the pump back a hair to make the in volume and out volume equal. I'd like the main tank water level to be near the black trim strip that supports the top of the tank, with that in mind, will this overflow perform in such a manner? Also, I have quite a bit of Cheato so I'm not really worried about being able to fill out the middle chamber. The last return area is drawn to be 10" of water and the way I understand overflows, that's where my water level will vary with evaporation, correct?

Questions
Is this designed correctly; as in, will the water levels be where they are drawn and the overflow is correctly sized?

Comments?


Thanks for taking a look.

Google Sketchup Document: Here

 

Unless your dimensions are off, I think you may just want to run a false back along most of the back of the tank. The do what you plan on doing there.

The return area is where you will see the evaporation.

 

Dimensions should be correct, although the full back is an interesting idea, you are talking specifically about the overflow area, correct?

 

I always thought a 40g breeder was 36"x18"x16". Your dimensions are way off from this. Is the tank actually a 40g cube or show tank? In any case, your setup is exactly like the back of a biocube or any other nano sold with a false back. Just better and will be to your needs.

 

Measured again, 17.5" x 15.5". I was off by 1/16 and 1/2". What thickness of material should I use? 1/8" glass? 1/X? plexi?

 

I would prefer to use glass over acrylic as the glass will bond much stronger with the silicon. That being said, acrylic can work, you just need to ensure you really silicone it well and it's easier to work with.

 

acryllic will work so long as its thick enough. i went crazy on my first sump design and used 5/8ths thick black acrylic with AGA sealant and it never moved.

in another sump i used acryllic with GE silicone and the acryllic gave way.

in my current sump i went glass for the high pressure zones and acrylic for the low pressure zones and it doesnt budge.

i like the idea here though. like others said, its like any other biocube design. false wall with multiple chambers in the back to handle whatever kind of filtration you desire. good idea.

 

I think all he would really have to do is make sure each compartment is water tight. The pressure from the tank part of the breeder would keep the acrylic in place.

 

The false back i pretty cool, they have one on the RSM250 that I have. It works well, but you might want to consider doing it along the length of the back, as stated earlier. Also, the portion for the return will vary by a huge amount because of evaporation, especially with that small of an area relative to the tank. You may want to make sure you get a ATO for this system; I have to top off mine every day, and it's a 65 gallon.

I don't see where you'd install a skimmer or any other filtration; this is a big concern of mine with these back-sump designs, as mine has been a gigantic pain to add anything to or change what the compartments are used for.

 

ATO is in the works. The return pump I'm going to be using is actually a modified Magnum 350 that I plan to run AC in. The skimmer sadly is going to be sitting in the main area running in hang on back mode. I looked at putting in in the filter area, but it requires 20" in width. It's not the end of the world, just a minor inconvenience. I wanted to have this division on the end of the tank because of the refugium is going to be visible. Running it on the back would provide far superior surface skimming, but at the expense of a much larger sheet of glass or plexi. Really great comments. Thanks 3Reef!