An in-ground swimming pool might easily cost $10,000 or more if purchased from a professional pool company. For less than $3,000, you can make your own that appears like it was professionally built. An in-ground pool needs to be at least five feet deep for child safety reasons. The bottom of the pool should be at least two feet from the ground in any case so that there is enough room for water to flow out of the pool when it gets too deep. You can build an in-ground pool from any of several different materials, but concrete is by far the most common choice. There are many different types of concrete available on the market today, each with its own advantages and disadvantages. Concrete is affordable and easy to work with, but also heavy and difficult to transport. It requires additional materials such as steel reinforcing bars for durability, and plastic or glass fibers for appearance purposes. The type of concrete you use will determine how much it costs to build your pool. Conventional concrete is made by mixing water, cement, and sand (or gravel) together until they form a smooth mass. The size of the particles in the sand matter because they determine how much heat is released when the mixture is mixed. A fine sand produces a finer product that sets up faster, while a coarse sand results in a coarser finished pool surface.