What is the recommended flow rate for the K+Advanced Filter?

We specify optimum flow rates for the K+Advanced Filters: - 6,000 litres per hour for the 20" K+Advanced Filter - 12,000 litres per hour for the 24" K+Advanced Filter - 18,000 litres per hour for the 30" K+Advanced Filter - 30,000 litres per hour for the 36" K+Advanced Filter