Nature's Ocean® Aqua Terra® Color-Coated Sand & Gravel 5 lbs offers natural gravel, sand, and acrylic-coated sand which won't disrupt the aquarium water chemistry, are non-toxic, and colorfast. Suitable for fresh and saltwater aquariums, ponds, terrariums, gardens, potted plants, vases, ash trays, crafts & hobbies, and architectural surfaces & landscaping designs, the product is available in the following sizes: 0.1- 0.5mm, 0.75 - 1.5mm, 9.5 -12.7mm, and 9.5 -12.7mm.