Separating sand from aquasoil areas

Sometimes we want to use soil in planted areas of the aquarium, while using cosmetic sand to create a path or beach in part of the aquascape.

For convenience, many aquascapers now simply lay a thick layer of sand over the aquasoil in the areas where they require cosmetic sand. The layer of sand must be thick enough to prevent the aquasoil from floating up. Hardscape is usually used to border the sand.

Plants with deep roots should not be planted in such areas, otherwise aquasoil will be pulled up during replanting cycles. If aquasoil rises to the surface of the sand, simply vacuum it up with a siphon during water changes. Due to the low organic content of Aquasoil, this method of building up a thick layer of soil won't cause any problems in the long term.

For those who wish to keep the areas separate, there are a couple of approaches; the first is to grow a carpet that overlaps both areas - the plants will keep the soil from both areas separate. Carpet plants such as HC and MC work well. For larger structures, Limnophila vietnam and Staurogyne repens work well as they do not require frequent replanting.

The other way is to line the path with rocks/coarser rock, which forms a heavier border that keeps the two areas separate. This is where having smaller pieces of rock to match the larger pieces can be very useful.

Using plastic sheets as dividers tends to create an unnatural look and plastic is easily visible between sparsely planted areas, so I do not recommend this method.