The term "hardscape" in the Nature Aquarium and in aquascaping describes all natural decorative materials like for example driftwood or rocks. As counterparts, aquatic plants, as they are basically the soft elements in an aquascape, are called "softscape". In aquascaping, the hardscape is used as decoration, and it is valued at least as highly as the aquatic plants used in such a layout. This is especially true for rock landscapes in the Japanese style (aka Iwagumi). When planning and setting up a layout aquascapers pay great attention to especially beautiful material (for example with an interesting texture or form).

Rocks

Basically we discern between rocks that are neutral in water and rocks that slightly harden the water. While rocks like lava or dragon stones do not influence the water quality, especially those rocks with a beautifully rugged surface like for example Seiryu Rock or Grey Mountain Stone do contain a little lime and thus may harden the water a bit. Especially if you have a CO2 injecting system in your aquarium, the carbonic acid produced by it has the potential to dissolve the lime deposits contained in these rocks. This increases the carbonate hardness as well as the total hardness of the aquarium water. In order to keep the water hardness down anyway we recommend changing larger amounts of water frequently. Use demineralised water or water from a reverse osmosis system to refill the tank.

It is highly recommendable to clean each and every piece of rock thoroughly or at least rinse it carefully under running water before you place it in your aquarium. Doing so you'll remove tiny dust particles that would otherwise cloud the water, especially in new tanks. Especially Dragon Stone, also called Ohko Stone, is notorious for containing loam deposits in its many nooks and crannies. Remove those with a sharp object and rinse the stones very thoroughly before you place them in your tank.

Driftwood

There are different kinds of driftwood that are suitable for aquascaping. The density of the wood differs. Wood with a low density, like Red Moorwood or Talawa Wood tend to float in the beginning. These woods need to be pre-soaked so they can absorb sufficient water to keep them down later on in the aquarium, or you can weigh them down with pieces of stone. Wood with a higher density, like Mangrove Wood or Riverwood usually does not have much buoyancy and stays on the ground from day one. Please make sure that it stays down for every individual piece of wood before you start using it in a layout, though.

Especially those woods with a higher density tend to give off humins to the water, which may add a brownish stain. If you prefer crystal-clear water from the beginning, we recommend the use of the filter medium Seachem Purigen. It has the potential to remove any tint in the water within a very short time.

By the way, it is absolutely normal for some pieces of driftwood to develop a white slimy layer, which is of bacterial origin. These bacteria are absolutely harmless, and the layers disappear after some time all by themselves. Especially snails, shrimp and some fish are even grateful for this additional source of food.

How to choose

In order to make your layout detailed and varied, it is recommendable to use different sizes of decorative materials. Rocks and pieces of driftwood can be manipulated with tools, for example to get smaller pieces.
Make sure you have a number of pieces of hardscape to choose from so you can try several layouts and variants. This will give you alternative design options.
Of course, driftwood and rocks can be combined. This makes the aquascape look even more natural. One thing to avoid would be mixing different types of stone or different types of driftwood. If you use various types of stone the whole picture will lose its harmonious effect.
The hardscape may look very dominant and massive before planting. Always keep in mind that the plants will later on cover around half of the decoration that is visible in the unplanted tank.

Source: Aquasabi