Overflow box for a drilled 30 cube

[testhead1313]

I'm starting to set up my new tank and would like some input as to the design of the internal overflow box and plumbing. The tank has three holes drilled in the back wall - 2 on either side and 1 in the middle for a drain. The tank was drilled by a previous owner and he used just a simple strainer basket as the drain - neurotic about leaks as I am, I think a proper overflow box is more desireable. Here's a pic of what I'm working with:

The middle hole is large enough for a 1.5" bulkhead and is 2.5" (on center) below the bottom of the trim lip. My questions are as follows:

1 - Should I do a full length box (from water surface to tank bottom) or a stand alone box (think hang-on overflow box-like)? If I did full length, I'd worry about detritus collecting at the bottom due to lack of water motion - also, it seems like a waste of perfectly good tank space.

2 - How many, how wide, and how tall are the overflow teeth? I want the water line to be above the bottom of the trim so I cannot see it. Is there any way to determine what this will entail? I will be using a QuietOne 3000 return pump that will encounter a T, 2 90s, and will have the standard 4' of head. The RC head loss calculator states I will be pushing 543 gph. Any ideas?

3 - For plumbing, I think an internal durso would work best as I want to keep the tank fairly close to the wall (ie, I want a 90 off the drain bulkhead in the back, although, I suppose a T would take up the same amount of room, huh?). Any opinions as to the best and most silent way to do this?

4 - I have some old overflows that I was planning on recycling into this project. Any opinions as to the bes way to cut this? Also, a router the best way to make the teeth?

Thanks for any advice!!!
Chris

 

[testhead1313]

Okay, so after doing a bit more reading, it looks like I'm going to do a pseudo-"calfo" overflow and have the box a few inches deep and as wide as the other 2 bulkheads will allow. Now, internal or external durso and teeth or teeth-less? According to RCs drain calculator, I only need 9 linear inches of overflow to accomodate 600 gph, does this cound right? Thanks!
Chris

 

[Ray]

I would do 2 corner boxes with the center hole for the return line

 

[testhead1313]

Any particular reason why Ray?

 

[Ray]

If 1 drain clogs you will have another

 

[Bobbofin]

I'd do an overflow across the whole thing about 5" tall like the tanks at Aquarium Gallery and put gutter guard on top to keep the fish out, a street elbow facing down on one of the holes with durso external drain. Plug one hole, two 2-1/2" pieces of glass. That will never leak in the overflow. Use other hole for return with flexable tubing over the edge of the overflow with nozzle like on the All-Glass Megaflow overflows. Just my opinion & $.02.

 

[smcnally]

I'd do an overflow across the whole thing about 5" tall like the tanks at Aquarium Gallery and put gutter guard on top to keep the fish out, a street elbow facing down on one of the holes with durso external drain. Plug one hole, two 2-1/2" pieces of glass. That will never leak in the overflow. Use other hole for return with flexable tubing over the edge of the overflow with nozzle like on the All-Glass Megaflow overflows. Just my opinion & $.02.

Why block one hole when you could use it as a second drain?