I use common playground sand in my 30 and my 125. It's soft on the fish belly, they can dig in it, plants root well in it, and snails turn it up pretty well. Wash it heavily to get the smaller, lighter particles out. Anything that does'nt settle in 10 seconds gets thrown out.
Mostly it's not too hard to keep clean. Water current helps to collect it, and as cheap as playground sand is, who cares if you suck some out in the water change. I do finger sift it to keep the bacteria low, and the bubbles out. I'm actually considering adding some gravel to the mix.