I have live sand in my 24 gallon salt water aquirum and im running out of sand and my dad has coral sand, I was just wondering if i could mix live sand and coral sand toghter.?

I'll be replacing the gravel in my tropical tank with inert sand, as I understand it's easier to keep clean with the fish-poop resting on top of the sand bed rather than sinking and hiding between large gravel gaps. But having never used sand before, what's the best typeto look out for? I already know to avoid coral sand due to its water-hardening properties. What colour do most people use? I want something that's natural-looking resembling tropical environments. A shop showed me silica sand, but that was too creamy in colour and unnatural looking, and that was the only colour he had. Does silica sand come in all colours, as I'm wondering if black sand, silver sand, etc, are all different forms of "silica sand"?

I thought having a silica sand bed at the bottom of the tank is supposed to give an easier life than cleaning gravel? Lifting the poop from the top of the sand bed I have no problem with, using an electric gravel cleaner. But what about the poop that buried inside the sand, how do I get rid of that? I was told to stir the sand to kick up any muck that's inside it, and the sand will settle with the muck (which is less dense than sand) settling on top where for easy removal. But that's not working with me. I do uncover a load of poop on top of the bed and I remove that, but when I stir the sand again, more poop gets uncovered. It seems I'll have to do the process a hundred times until the substrate is totally clean. What's the best way to keep sand clean? What am I doing wrong?