I have sand, I have a community tank, It is overstocked, It gets poo on it all the time, I only water change once a week.
Guess what
Its natural guys. You seriously want a tank where you can't see fish pooh then don't buy fish, otherwise get planted and let the plants take the natural fertiliser.
I don't see the problem, once a week I remove whats on top, then the process starts again, the plants use some, the bacteria use some, and then at the end of the week I remove whats left, and on and on.
Fact of live fish do pooh. Apart from not likeing gravel too much. it gets filthy with all the mulm working its way to the bottom over time. I'd rather see a few bits of poop on the sand then have gravel where especially against the glass ou can see how much s**t actually gets into it!! Yuck
It is Argos play sand and it doesn't get into my filter (which is internal) because my filter is about 4 inches off the sand and it won't get sucked up that high.
EDIT: please excuse my over authoritous tone in this post. got a bit carried away there