I'm new to glass drilling, but with the right tools and patience it so far seems pretty easy. I don't see a problem with drilling a hole in the side a few inches from the side and bottom, it could be hidden pretty well this way if you have a land feature up against the glass here. The dangers are much less than with a big giant reef tank- you have much less water in case things go bad, you can probably put the hole above the water level and still be discrete, and you can make it a very small hole if you are comfortable cutting the power cord to thread it through (which opens up another danger of course).

You can probably find someone experienced near you to make the hole for you as well.