Also looking for opinions on this live sand

[Kryten]

Thanks again. I'm planning to setup a small system ~20gal in my living room with minimal anything. I'm a fan of the theory that with enough live rock you don't need to do much to the tank, so I won't have a sump or fuge or any filters. Maybe just a small air-driven protein skimmer. I'm also not really planning to try and keep any particularly finicky corals.

I also have a 45 gal tank in my office that I want to switch to sand from the rough crushed coral (.5-1 cm) that I have now. So I guess the key to having sand then is to make sure you have just enough flow to not mess it all up? I don't really like the look of a tank with no substrate. What's the best grain size or type to use to maximize the bacterial filtration? Also am I best off going with a dsb of 4 inches or so, or is an inch or two sufficient?

Thanks!