This 12-inch x 21-inch carbon filter is an excellent addition to your hydroponic system. Designed to remove impurities and unwanted substances, this filter is perfect for ensuring that your garden is clean and healthy. With a single pack of carbon media, this filter is ready to use right out of the box. The item diameter and length are 12 inches and 21 inches, respectively, making it a great fit for most hydroponic systems.

This carbon filter is perfect for those who want to ensure that their garden is clean and healthy. Whether you're a professional hydroponic gardener or just getting started, this filter is an essential tool for maintaining a healthy environment. With its high-quality construction and easy-to-use design, you can trust that this filter will help you achieve the best possible results.