drilling glass

I have a handful of 30g and 40gb glass tanks with holes drilled into the upper back glass panels. What is the best way to fill in these holes? I’d ideally like to do bulkheads with caps, feel like this will be a cleaner look over glass sheets since it’s at the top of the back panel. Any videos...

I have drilled quite a few tanks so I got that part no problems there. I am thinking of putting together a fry rack with a central sump filter. I was going to use ten gallon tanks from Walmart, for me this is the cheapest option. Does anyone know if the tanks from walmart are tempered or not...