Shop / Products / Estes Spectrastone Blue Gravel Estes Estes Spectrastone Blue Gravel Weight: 5 lb $14.99 5-lb Purchase Options Pick up in Store Not Available Set your store for inventory and store pickup details Zip Code Search Ship to Me Not Available Quantity Add To Cart Information Ingredients Spectrastone blue gravel is an ideal substrate for fresh water and marine tanks. Our standard colors use silica quartz which is an inert stone that will not affect pH. N/A Customers also liked Customer Reviews