All in Ones (AIO) have an appeal for those who do not like to see plumbing, wires, skimmers and all the other bits hanging off a tank. I'm not saying that you can't have a ground up tank look clean with no visible parts hanging off, just look at some of the better build threads to see examples
AIO are built for display and beauty, they may not be able to host the exotics but they sure look fine and they set up quickly.
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