Counter Current System

In a counter-current system in a pool, for example, water circulation or filtration systems may be designed so that water flows in one direction while the cleaning or treatment process occurs in the opposite direction. This setup is often used in various industrial processes and water treatment systems to optimize efficiency.

It seems like there might be a small confusion in your question. If you are referring to a "counter-current system" in the context of a pool or water treatment, it typically relates to the flow of water in a system where two fluids (or substances) move in opposite directions.