As dirt accumulates inside a filter, what happens to the amount of water that can pass through it?

As dirt accumulates inside a filter, the amount of water that can pass through it decreases. This is due to the fact that the buildup of particles creates obstruction within the filter media. As the filter traps more dirt and debris, its ability to allow water to flow through diminishes because the flow paths become narrower. Consequently, the pressure on the filter increases and may lead to reduced water flow rate, potentially resulting in backpressure that can affect the overall circulation system. Regular maintenance, including cleaning or replacing the filter, is necessary to ensure optimal filtration and water flow in a pool system.