I received my free sample of small casuarina cones along with the small alder cones sample yesterday. Within 24 hours with one of each cone being in the tank, the water on both tanks is completely 'black' and fully tannin stained. For those that want black water it is completely essential for these cones if you don't want Indian almond leaves in the tank, which are larger and break down faster. Yes I cheated by using the same review as I wrote for the alder cones, but since one of each was placed in the tank yesterday, I figured it was justified.
Thank you for great products.