From the combination of warm temperatures and high propulsion water flow to the intimate bathing environment, the filtration needs of a spa are very specific and fundamentally different in many ways from swimming pool filtration. Spa and pool replacement filter cartridges have always been assembled using the same design and materials for both environments. As an industry leader in science and innovation, Pleatco began researching, developing and successfully creating the first premium, scientifically engineered spa filter cartridges!