Drilling Glass Tank

[carlos_fb]

I have a 60 gallon tank 48" x 15" x 18" which I plan to drill to add an overflow box. I was wondering how big the holes have to be in order to create a good flow? I also plan to add a 20 gallon tank as a sump.

[Geoff]

how much flow do you want through the sump? i like to keep the flow through the sump equal to or less than the flow through the skimmer. i would not think you would need to have an overflow handle more than about 600gph. in this case a 1" bulkhead would do the trick. every manufacturer of bulkhead has a different hole size needed for their bulkheads. i would not get the hole saw untill you have decided and purchased the bulkhead.

G~

[super633]

I whish there was a way of telling if glass is temered. I love to drill the bottom of my tank but I don't have the nerve to do so.

[Sprayin70]

Check out my 20 long build or my blog. I drilled a 20 long today. it was the first time I have ever drilled a tank. I used a dremel glass kit and sprayed the tank with water every few seconds.

[carlos_fb]

Originally Posted by Sprayin70

Check out my 20 long build or my blog. I drilled a 20 long today. it was the first time I have ever drilled a tank. I used a dremel glass kit and sprayed the tank with water every few seconds.

Man you're brave! thanks for sharing the pictures, it looks good!

[Sprayin70]

Thanks, Just jump in. LOL

[seaham358]

Like Geoff says it depends on what type of BH you use, most you will need a 1 3/4" diamond hole saw for a 1" bulkhead.
I have all my tanks drilled in the upper corners with the bulkheads and then have elbows with strainers on them so I have no ugly OF box in the tank. I get great flow like this.
Most tanks have a tempered bottom so I would not try that. Check with the company that makes the tank to make sure your tank is not tempered. I had a 55 drilled at the LFS and it burst when the hole was about half done. It was tempered
I drilled a 37 tall and 90 about a month ago, the key is keeping the bit cool at all times. use plenty of water or the special glass drilling fluid.

[Sprayin70]

can you post pics of your plumbing?