*Product May Be Subject To Extended Lead Times. The UltraZap 1 Bag Fibreglass Sand Filter is designed for koi ponds up to 5,000 liters. Constructed from high-quality woven fibreglass, it offers durability and efficient mechanical filtration by removing solids before water reaches the biofilter and UV sterilizer. The top-mounted lid allows for easy access and backwashing. Note: Koi filter sand is not included and must be sourced separately.