What is the main purpose of main drains in a pool or spa?

The primary role of main drains in a pool or spa is to facilitate the removal of water and any debris that settles at the bottom. By doing so, main drains allow for the effective management of water quality and cleanliness, ensuring that contaminants and debris do not contaminate the overall water body.

While there are systems in place for enhancing water circulation and maintaining temperature, the main drains specifically target the removal of water that has debris or is saturated with contaminants from the bottom of the pool or spa. This helps to maintain clearer water and improve the overall sanitation of the pool environment. Without properly functioning main drains, debris could accumulate, leading to poor water quality and increased difficulty in maintenance efforts.