External "Calfo style" Overflow?

[bored4long]

I dropped by AquaLife today just to day dream and left with a used 125g AGA tank.

I'm toying with the idea of an external "Calfo style" overflow for it and wanted opinions on feasibility. I would prefer to have the overflow the entire 6 foot length of the tank. My main concern is the tank's structural integrity, since the center brace would need to be removed. I expect I would need to incorporate a euro-style brace on the front.

Know any local glass shop that could cut the rear and add the brace to the front?

Here is a good example of an external overflow:

 

[Jim_S]

I think you are asking for trouble if you cut that center brace. You may be able to slicone a new one in its place though....

I have also considered this approach. Calfo overflows are awesome. Pricey, but when done right, externals are the best type of set-up IMO.

You could also just do one on each side....

I was also thinking about doing mine in the inside. Just one long one down the middle. Gotta get a tank first though....:lol:

I'll be tagging along here

Jim

 

[eagleONE]

I love the cut. very clean. looks good

That's exactly how I did my tank.

 

[Doahh]

"I was also thinking about doing mine in the inside. Just one long one down the middle. Gotta get a tank first though...." Same here... 2 bulkheads in the back of the tank... one on 1 side one on the other

 

[bored4long]

Inside overflow is what I was first reading about, but I really didn't like the amount of room it would take. External is the perfect solution because you can go as big as you want and it will only add to your total volume. I love the idea and really want to make it happen.

I just checked and the 125g is 3/8" glass. Would be nice if it was 1/2".

<a href=showthread.php?s=&postid=10294809#post10294809 target=_blank>Originally posted</a> by jimdogg187
I think you are asking for trouble if you cut that center brace. You may be able to slicone a new one in its place though....

Looking at the attached pictures above, how would I add a replacement center brace? Just run it to the back wall of the overflow? I think I would use 1/2" for the overflow glass, so it might be able to support a new brace.

If anyone has any good links to center or euro bracing, please post them. I need to read up on them.

 

[Doahh]

You don't need that much room for an internal weir overflow... just make it tank long and 1-2 inches wide and 4-5 inches deep

 

[Jim_S]

Yeah, with that type of groove cut out, you wouldn't be able to secure a brace. You'd have to change you plans somehow.

As for the internal coast to coast (calfo) overflow, the main reason I want to do it this way is the LACK of space that it takes up. It would just run along the top, come out about 2-3" and down about 5". Not really gonna place anything like rock work along that top section of the tank.

Jim

 

[bored4long]

<a href=showthread.php?s=&postid=10296823#post10296823 target=_blank>Originally posted</a> by Doahh
You don't need that much room for an internal weir overflow... just make it tank long and 1-2 inches wide and 4-5 inches deep

This is true, but I would like a bigger overflow and that is why the external is more appealing to me. Also, if I want to incorporate a Durso then the internal overflow would need to be more like 3". I already plan on making the tank stand 6-8" deeper than the tank (tank is 18" deep, stand 24"+). So I will have room behind the tank to have an external overflow. The deeper stand will allow me to upgrade to a larger tank in the future if I wanted and keep the existing stand. Also allows for more room under the tank for a big sump/fuge and other stuff.

I'm not dead set against the internal overflow at all. It is just as good as an external in effectiveness. It will certainly be my fallback design if I can't pull off an external.

 

[eagleONE]

Now that I think of it, your overflow box doesn't really need to be that wide. In matter of fact, it would be better if the box was longer; There wouldn't be so much pressure at the top, because it's distributed down the tank wall.

This isn't the greatest picture in the world to illustrate this..but here is a picture of my back when I first started to build the tank. I designed the overflow to be longer rather than wider.

hope this helps

jay

 

[Doahh]

Why do you need a durso? I'd be fine without a siphon anything in it... it shouldn't make THAT much noise

 

[bored4long]

A Durso certainly isn't needed, but my wife is very sensitive to the noise of our existing freshwater aquarium and it just has a minor gurgle to it. So I need to do everything within my power to keep the new system as quiet as possible. (I think its a Durso that is used to quiet down the bulkhead.) I've seen examples of Dursos used for internal overflows as well if I have to go that route.

 

[Doahh]

hmm
let me draw something possible up

 

[Doahh]

Not the best but I did it freehand in paint

first is a side view
Next is the back view

 

[juaninsac]

I did this on my cube.

The box is shallow. You don't want a lot of weight hanging off the back of your tank putting more stress on an already compromised back pane. Also, consider what this will look like from inside your tank and how you'll conceal the overflow.

I did not use a Durso. I have two bulkheads, 1" and 3/4". The first is a primary drain with a gate valve. I reduce the opening on the gate valve until there is no noise; the drain is just matching the return pump output. It's a tricky risk because any variation in pump output (say after the pump restarts) could cause an overflow. Thus the second drain, which only receives a trickle of water. It's a bit more initial work to implement but, IMhO, is much much quieter and hassle free than a Durso standpipe.