Here in the USA we call 'grit' the small stones that chickens need for digestion, and oyster shell is not called 'soluble grit'. In the UK it seems that confusion reigns! The two items are not interchangable, your birds need both, in separate containers.
Both products will last for decades, so not a problem. However, having either soaking in water might promote mold growth, so containers that drain, or are out of the rain, are best.
Mary
Both products will last for decades, so not a problem. However, having either soaking in water might promote mold growth, so containers that drain, or are out of the rain, are best.
Mary
