I've found sand is almost as easy as gravel, it helps to slope it slightly towards the front as the then most of the solids waists fall down to the front. You can use a large gravel vac as normal and all but the smallest particles drop back down like the gravel does. I use river sand which I collect myself but you can buy lots of types from garden centres (don't pay more than $10 for a 20l bag!). Aragonite is great if you can get some (and I should really get onto it :oops: !) but using Limestone as rockwork does pretty much the same thing - keep in mind one or both of these is a must for Rift Lake Cichlids (AKA Africans) as Rollergirl said, to naturally buffer the pH.