General river sand can be used for fish tank landscaping, especially for raising fish in local water system, and local sand is the most suitable. Generally, sand is divided into natural sand, processed sand and artificial sand. Natural sand is naturally formed and easily obtained, but it often contains impurities. Processing sand is to break the natural sand, which is irregular and looks unsightly. The artificial sand is made artificially, which is highly ornamental and colorful.

1. Planting aquatic plants: The first advantage of spreading sand is that you can plant aquatic plants. There is nothing at the bottom of the bare tank, so you can't plant aquatic plants. With sand, you can fix them. However, it is better to use aquatic plant mud, which is more nutritious and suitable for the growth and development of aquatic plants.

2. Favorable culture bacteria: There are not only fish in the fish tank, but also many beneficial bacteria, and the health of fish cannot be separated from them. These beneficial bacteria often need to be attached to something, and with sand, it is convenient to cultivate bacteria and establish a good nitrification system, thus transforming harmful substances such as ammonia nitrogen in water.

3. Purifying water body: Although cultivating bacteria can also purify water quality, it is the credit of beneficial bacteria, while the situation of purifying water body with sand is different. With sand, some dirt can fall down and avoid floating in water, which will lead to turbidity of water body.