Filter-balls are made from polymer fiber. It is a direct replacement for traditional sand, making it suitable for above wood-fired hot tubs.

• Excellent filtering result, removing particles
• Does not stick together or harden like sand does
• Very easy handling due to low weight
• Low cost, 350 g for an equivalent of 25 kg of sand
• Easy to dispose of with standard domestic waste
• Less pressure increase and energy saving
• Less repairs, no problems or defects on seals
• Resistant to swimming pool chemicals

350 g filter-balls = 25 kg sand