i just started using sand. planting is a breeze, but after pruning stem plants, the rootless tops can float easily until they root again. fine sand can compact and, supposedly, make it hard for roots to develope, pool filter sand is a heavier grain that will help with this problem. it still looks great and is less cloudy. sand doesn't have any nutrient value, so layering it over something like ADA aquasoil or laterite will do wonders for rooted plants, but they will eventually mix after a lot of rearrangement. anarobic pockets can build up over time, so sand needs to be stirred about once every month or two, malaysian trumpet snails help this process a lot.