Hello every one

I'm going to build my own sumb. I was thinking if doing it out of acrylic for 2 reasons. It would allow me to customize it as I wanted it As well it would give me practice for when I want to make my own larger acrylic tank.

I understand how a sumb works and how to build it. The area that I'm still the most confused about is the overhang box. wont be drilling my Aquarium. Its made of glass and has live fish in it already. With this being the case I will have to do something else. I would rather have my overflow box on the inside of my aquarium for the simple fact I want to minimize all my risk. Any ideas on how I could do this. Iv read that you can use a specimen box and hang it on the inside of the aquarium and then run your plumbing from that down to the sumb.

The other thing I'm still struggling to wrap my head around is how to get the water from the overflow box to the sumb without using a pump. Online they seem to use a T at the high point of the plumbing as it comes up from the over flow box heading to the sumb of the aquarium and they poor water in this T to start a siphon. Does this really work? What are the draw back to doing this?

I'v read that it helps to have two inflow pipes running from the aquarium to the sumb. How would you do this when you are using your own overflow box with out drilling the aquarium?

I would love to hear from people who were just as confused as I was and how they figured it out. Any helpful links or diagrams would be very helpful. Any last helpful tip or ticks to make and maintaining a overflow/sumb filtration system.

Thank you for your time I looks forward from hearing from you all.