# hang-on overflow



## zig (Oct 7, 2005)

What do you guys think of the hang-on overflows to a drilled tank???


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## Ægir (Jan 21, 2006)

Drilled is better... some tanks cant be drilled so you have to go hang on overflow. If setup properly, hang on overflows can be nearly fail-safe and flooding wont be an issue.


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## zig (Oct 7, 2005)

has anyone drilled there own tank by them selfs if so what kind of hole was used
how do you tell is glass is tempered glass


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## Ægir (Jan 21, 2006)

zig said:


> has anyone drilled there own tank by them selfs if so what kind of hole was used
> how do you tell is glass is tempered glass


I have drilled one tank myself, but usually have a guy at my LFS do it because he has a drill press (with water)

You use a diamond tipped hole saw, something like this clicky and LOTS OF WATER. Also dont apply pressure, let the drill and drillbit do the work

Telling if its tempered or not is a bit tricky... what brand of tank (where did you buy it?) because some have charts. Better question, is how thick is the glass, and what are the dimensions of your tank?


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## zig (Oct 7, 2005)

the glass is 1/4 around there is a 50 gallon long 4 feet by 18 tall 12 wide thats at least few years old not shure i had for almost 2 years then mom got it from a guy that was using for saltwater


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## Ægir (Jan 21, 2006)

zig said:


> the glass is 1/4 around there is a 50 gallon long 4 feet by 18 tall 12 wide thats at least few years old not shure i had for almost 2 years then mom got it from a guy that was using for saltwater


If its 1/4" thick you are prob safe... if its 1/8" thick you prob arent.

Get a tape measure and check it out


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## zig (Oct 7, 2005)

its really close to 1/4 not close to 1/8
its good to be shure dont want to start to drill tank and crack


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## Ægir (Jan 21, 2006)

zig said:


> its really close to 1/4 not close to 1/8
> its good to be shure dont want to start to drill tank and crack


You can also use a polarized lens to see the tempering.

Use google and check it out more


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## zig (Oct 7, 2005)

the first time we filled this tank for mom the bottom glass cracked and had to be replaced im think since the bottom didnt explode im thinking the tanks not tempered glass unless they use diff glass for the sides
the bottom of he tank was two pieces of glass if you can tell how old the tank was with that?


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## CLUSTER ONE (Aug 2, 2006)

I have a hob overflow. Drilled is better, but hob is great if you dont want to drill or adding to an existing tank. The main thing is make sure the water is going fast through the siphone tube so that bubbles wont form at the top and break siphone


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