Hi, I am brand new to aquariums. I had a small freshwater aquarium growing up but now I’m wanting to get a large saltwater aquarium for my kids. I’m don’t even know where to begin. Do I need one with a built in sump or is there a difference between the physical aquarium between salt vs fresh and how do I get everything set up? I’m not really concerned about cost, just don’t know where to get started really. Think I’ll probably buy a used aquarium off Craigslist but other than that I don’t know what to look for. I’m thinking 200 gallons or more, and I would greatly appreciate any advice. I am a complete novice so any help is appreciated, really want to do this to get my kids involved. Thanks!
My advice is to decide which fish you want and then design your system around those fish.

