Cap Stone as a filter media

Found this at a nursery while doing research on another project.

The product is called Cap Stone and is used for indoor pot planting to provide drainage. It's inert (tested with vinegar) and very porous. I have compared it to Matrix which has slightly smaller pores. In my opinion its a viable alternative to Matrix and it certainly is cheaper. One liter would cost about R40, not bad. Unfortunately they didn't have any of the original packaging for me to see who the manufacturer is.

Anyone know of this product?

 

This is not the matrix you are looking for"
It looks good and very porous it looks promising

 

Does it float if you pop it in water @jedigenie? Must be a form of pumice stone then ... Should be fine if the channels are open and it sinks... If they are closed - you'll only get bacteria colonizing the surface.... Not ideal...

 

It does sink but some stones do float initially (like Matrix does). Once the trapped air bubbles escape, it sinks. The similarities to Matrix is quite remarkable.

 

Think you found a gem there then @jedigenie...

 

Hence the reason I rushed home to share with my fishy pals

 

Gonna go raid the planters in the office on Monday....seem to think they have the same stuff in them...He,he