What is the maximum flow rate per square foot for both pressure and vacuum type DE filters in public pools without slurry?

The correct answer reflects that the maximum flow rate per square foot for both pressure and vacuum type diatomaceous earth (DE) filters in public pools without slurry is set at 2 gallons per minute (gpm). This standard is based on guidelines designed to ensure effective filtration while minimizing the potential for channeling and other inefficiencies that could jeopardize water quality.

Maintaining a maximum flow rate at this level helps to optimize the filtering process by allowing the DE filter media to capture particles effectively without overwhelming the system. Higher flow rates can lead to inadequate filtration, resulting in poor water clarity and increased risk of contaminants remaining in the pool water.

In comparison, options suggesting higher flow rates exceed these recommended standards and could risk operational efficiency and water safety. It is essential for pool operators to adhere to these guidelines to ensure compliance with health standards and provide a safe swimming environment.