Awesome information guys! Thank you so much! I'm thinking that i want to put a sump on my 100 gallon. (Probably a 40 gallon breeder or something similar.) so that really helped me understand kind of how to put it together, because I will be building it.
Kevin, thanks for following.
I would definitely love to put an ATO together. I will probably go with whatever is cheapest. If I am going to have a sump, there's no excuse not to have one. Lol.
Do y'all by chance know who to contact to drill my tank? Like a window shop? Do they have just standard glass shops? I've never done this before. Kind of my first high tech-ish setup. I definitely have to drill this tank to have a sump. I live in an apartment, so it's really really important to have a proper over flow back into my display. Too much liability with 140+ gallons of water. Lol. I can't risk gravity draining it all!
Thanks for the great responses. I'm really trying to learn and research before I do anything at all and I'm prepared to wait to set this up correctly. I feel like I rushed into my 55 a little. I don't want to make the same mistake again.