Fiberglass swimming pools do not require a liner because their shell is coated with a highly durable finish. They come in a wide variety of sizes, colors, and shapes and allow for customization that many consumers enjoy. Fiberglass pools are easy and quick to install without needing heavy equipment. While fiberglass pools require less maintenance, they still need some upkeep to prevent damage and require larger repairs later on. Unlike other pools, fiberglass pools must always be filled with water to avoid cracking or warping from ground pressure caused by emptying.