Brick shards

The only info available is: Brick shards have similar properties to gravel. They have the added disadvantage of possibly altering the pH and requiring extra cleaning before re-use.

That’s true but not the full story.

When we talk about “Brick shards” we talk about bricks made out of clay and not Concrete.

The clay bricks can be separated into two groups:

a) The old fashion low temperature clay bricks; and

b) the modern, fire resistant, high temperature bricks.

Old fashion bricks do decompose releasing various nutrients, like iron in to the soil. They are also porous, absorb water better and retain moisture.

The new, modern bricks contain additives that improve the strength of the bricks and make them fire resistant. These bricks are produced at higher temperatures and do not decompose easily. They are like “expanded clay pellets” only angular and shouldn't be used.

Old style bricks shards, crashed to size, could be placed as a layer above perlite, sphagnum moss, small coconut chips, coir or other light medium to prevent any loss from floating away during watering.