Asking about both really. Sump is priority one. whats the min. gph on that and is it adjustable?
Depends on what you are keeping as to how much flow you want as well. I used a Mag 18 in my 46 gallon bowfront (about the same measurements of your 50 gallon I believe) and also had an Vortech MP10 in it as well, but that is because I like having a lot of current. While the Mag drives are convenient (submersible), they aren't as quiet, nor as flexible as having an out of pump sump.
Not so much visual even as a deep sand bed helps turn mutated into a gas and remove it from ur tank. There is a lot of info on deep sand beds benifuts and cons do a search u will finger hours of reading
LOL Just kidding Roger. Kinda reminded me of the instructions that come with foreign made products sometimes.