Nature Aquarium uses Aqua Soil as the main substrate material. As discussed in the feature article of this issue, there are various types of substrate in a natural environment, including sand, pebbles and mud. Aquatic plants grow densely on some types of substrate while there are no plants grown on others. Usually, aquatic plants grow well on muddy (or soil) substrate but they do not grow well on sand or pebbles. Except in the case where a non-plant growing place is reproduced using cosmetic sand or Aqua Gravel, the Nature Aquarium uses Aqua Soil for the sections in which aquatic plants are to be planted. Made from natural soil, Aqua Soil contains rich nutrients such as nitrogen and trace elements found in natural earth as well as abundant organic matter such as organic acid. This series of soil  effectively promotes the healthy growth of aquatic plant roots and activities  of  beneficial  bacteria.  Aqua  Soil Amazonia made from black soil contains particularly  abundant  nutrients  and  organic matter. This feature makes the Aqua Soil Amazonia the most effective soil in aquatic plant growth among the Aqua Soil series, which is why this soil is used the most in Nature Aquarium layouts.

The typical way of setting up the substrate currently used by the Nature Aquarium Gallery is the combined use of substrate additives including Bacter 100, Power Sand Special and Aqua Soil-Amazonia. However, use of Aqua Soil Amazonia may lead to cloudy or discolored (yellow) water during the initial stage of the aquarium due to the abundant nutrients and organic matters contained in it. These problems will be improved through frequently repeated water change and eventually be solved by the time  the  entire  substrate  is covered with aquatic plants. Nevertheless, beginners who do not have much experience in aquarium layout may get anxious about these problems. Moreover, the problems of cloudy or yellow water may not be improved if the substrate is left unplanted.

To  address  these  challenges,  Aqua  Soil Amazonia II has been developed as the substrate  material  which  is  manageable  for aquarium beginners. Aqua Soil-Amazonia II has lower amounts of nutrients and organic matter compared to the original Aqua Soil-Amazonia; instead  it decreases the chance of causing cloudy or yellow water by its characteristic of effectively making the tank water slightly acidic. These features have been further enhanced for the current version of Aqua Soil-Amazonia II and, on top of it, an improvement was made for this soil to make its grains less crumbly.

For the applications of Aqua Soil-Amazonia and Aqua Soil-Amazonia II, it is recommended  to use Aqua Soil-Amazonia if you have some experience with aquariums and wish to give first priority to the growth of the aquatic plants, while Aqua Soil-Amazonia  II  is recommended  for those who want to leave the substrate bare and make the tank water slightly acidic. Of course, most aquatic plants grow well just with Aqua Soil-Amazonia II which is therefore suitable for those who are producing the Nature Aquarium for the first time. Meanwhile, Aqua Soil-Africana has a higher water acidifying effect but fewer nutrients than Aqua Soil-Amazonia II. This tendency is further enhanced for Aqua Soil-Malaya, which lowers the pH level of the water but contains only a limited amount of nutrients. It is recommended to choose the type of Aqua Soil to be used based on each user’s priority, i.e., the whether the user places priority on acidic water or the growth of aquatic plants, rather than based on the color of each soil.