There are several types of above ground pool cover, each with a specific purpose. The benefits of a pool roof depend on the type of covering you choose. As an example:
The solar layer above the ground
Above-ground customizable pool covers are typically used in early spring and fall, often in conjunction with pool heating. Sunshades are like "balloon wrap" for your pool. It usually consists of two layers of vinyl separated by an air pocket.
Image Source: Google
During the day, sunscreens can raise the temperature of the water by several degrees, but the real benefits come at night when the air layer acts as an insulator to retain the heat generated during the day. This type of cover is not suitable for winter covers.
Pros: It helps retain heat, prevents evaporation, and helps maintain the chemical balance in your pool. Easy to install and remove – often used with a solar roller.
Hard surface for above ground pools
The hard pool cover has a long service life. This lid is held in the pool with a water bag or ballast, tongs or other shells. The challenge is to maintain coverage despite strong winds or other storm conditions.
Pros: Provides a closed environment that protects from dirt and pollution, inhibits algae growth, and maintains the integrity of the chemicals in the pool.
Cons: These covers accumulate water, which poses safety and health risk. Options for dealing with this problem are 1) mesh panels on the lid that allow standing water to flow into the pond, or; 2) Pumps for covering the pond. This will not prevent drowning.