Once you get your new tank and your tank additions, you will need to wash them in warm water. Do not use any soap or detergents to wash the gravel, rocks, or ornaments, just warm water. This will ensure these items are free of dirt, bacteria, and toxins.  You can wash the gravel by placing it in a colander. Put the colander over a plastic pan or bucket and add water to the colander with the gravel. Stir the gravel around, drain it, and repeat this several times until the water runs clear and clean through the colander. Once these items are clean, you can add them to the tank. Make sure the gravel is evenly distributed at the bottom of the tank. Place the rocks and ornaments in the tank so there are hiding places for your fish to explore. Use a clean bucket to pour water into the tank. Place a plate or saucer over the gravel as you pour in the water so the gravel does not move around.  Once you have filled the tank one-third with room temperature water, you should add water conditioner or dechlorinator to remove the chlorine from your fish. Chlorine in the tank water can be deadly for your fish, and/or lead to health issues. You may notice that the water turns cloudy within the first two to three days. This is due to bacteria growth and should disappear naturally. You should have an air pump in your tank to ensure there is enough oxygen in the tank water. You will need to connect the airline tubing from the air pump to air outlets in your tank, such as an air stone. You may want to use an aquarium check valve, which is a small valve located outside your tank to hold the air tubing. This will allow you to then place the air pump underneath your tank or aquarium. The valve also acts as a stop and prevents water from backing up in your tank if somehow the power to the tank is switched off. Live plants are good for circulating oxygen in the tank water, but you can also add plastic plants to create hiding places for your fish. You can also use the plants to hide any equipment in the tank that you want to disguise...

TL;DR in Vietnamese:
Rửa sạch sỏi, đá và các vật trang trí. Tích nước ở nhiệt độ phòng đầy một phần ba hồ cá. Kết nối máy sục khí. Trồng thêm cây giả hay cây thật. Tuần hoàn nước trong hồ bằng bộ thiết bị tuần hoàn. Kiểm tra chất lượng nước.