This is a high quality washed lava. It is a substrate that can be used both for the bottom of the pond as well as in the filter. Thanks to the volcanic origin and the extremely high temperatures that were present when they were created, the lava chunks are very porous. It is also safe for plants and fish.
The plentiful pores of this rock offer space for the development of millions of water purifying bacteria. By using pond lava at the bottom of the pond and in the filter, the bacteria can multiply and as a result, the self cleaning ability of the pond increases tremendously. The adjusted granule size (8-16mm) ensures an optimal flow of the water through the filter. In addition, it ensures maximal porosity and a faster breakdown of the sediment at the bottom of the pond.
Pond Lava is perfect as an embedding sunstrate for oxygen plants and wetland plants. This porous substrate ensures a good flow of oxygen rich water for healthy roots and good growth. You can also use pond lava to cover pond plants baskets with water lilies.