I haven't used anything like this before, but for the prices, it seems like an unnecessary expense. I've used all forms of substrate from soil and sand to gravel and even marbles (Not my proudest moment).
There are cheaper ways to jump start your cycle for the same benefits the rocks claim to give you such as Seachem's Stability to seed the tank.
There are cheaper ways to jump start your cycle for the same benefits the rocks claim to give you such as Seachem's Stability to seed the tank.
