This a Diy on how to drill smaller tanks using a dremel tool.
I decided to turn my 15gal long guppie tank into a nano reef tank.
I picked up a small overflow and decided to drill the hole myself.
Since I already had a dremel, I went out and purchased a diamond bit to cut the glass. The bit is #7144 diamond point bit.
Here is the bit


I drew the outline of the hole with a sharpie.


Because I have such a large sink i was able to do this in the sink to keep continuous water flowing over the bit. You can also do this in your bathtub with another person pouring cold water around the bit as your cutting.



I turned on the water and started making a hole with the bit, I was a little nervous at first about cracking the glass. I made the intial first hole with ease.


Then started cutting. I found it cut a little faster and easier by moving the bit up and down like a saw as i put pressure to move it.

I went faster than I expected, this was only after a couple of minutes.


I had to stop every once and awhile to allow the cable to cool down on the dremel. After about 20 minutes the hole was cut. Unfortunatly mI forgot to take a pic of the hole, but itturned out better than I thought.


Just remember to wear safety goggles just in case the tank is tempered and decides to shatter on you. Also would be a good idea to wear gloves in case of a break.

Ive always been afraid of drilling any tank.Thanks for all the info.