Pumice stone is one of the most effective natural filters for ponds and tanks. Best placed in flowing water, the stone allows for helpful bacteria to colonise whilst also naturally filtering water. In ponds with filter systems, the mesh bag allows for easy placement and collection of the stone from the filter. In ponds without filters, the stones can be placed individually, or the bag can be submerged close to the pump to allow water to be drawn through it.

The stones range in size from around 1.5" (4cm) to 2" (5cm)

Always clean lightly with pond /tank water to avoid removing existing bacteria colonies.