1. 5-8cm natural black lava rocks, with drilled holes / without holes.
Lava rocks are a famous functional and decorating rock in bonsai aquariums. They are natural filters.
They are porous to let water go through.

2. I attached photos of a terrarium made of black lava rocks in the Buddha moss wall terrariums. The saxifrage is planted in the drilled lava rocks.

3. In my terrarium projects, I plant small plants like fittonia and small ferns in the drilled lava. I restrict the roots so they won't destroy the live moss wall.
There are many other ways to use lava rocks for bonsai, moss, and micro landscaping, like the one in the main photo. I glued lava rocks together and used red clay to stick the moss on them. The other moss project in the blue-framed fish tank was done like that for one of my local buyers. It is glued lava rocks behind the moss.

4. If you do not want polystyrene to build a landscape in your terrarium. Those rocks are the best alternatives.

5. It is ideal to grow moss. Those with holes are made for planting small terrarium plants and will help you create a vertical landscape.

6. Ideal for container garden, jar, terrariums, aquarium, paludarium, vivarium.

7. It goes well with plants like moss, orchids, succulents, cacti, and bonsai trees

8. Size: 5-8cm

9. Weight: 500g