Bag of sand and gravel for swimming pool filtration

- One single reference to simplify stock management - Ready-to-use bag: sand + gravel in one package - Consistent mix ratio: 80% silica sand / 20% gravel - Graded and washed silica sand - Ensures mechanical water filtration - Denser basalt gravel for easier placement - Compatible with all treatment systems - Saves time when preparing and loading the filter - Reduces on-site dosing errors - Simplifies purchasing and storage