Fluval 12694 Plant and Shrimp Stratum for Freshwater Fish Tanks, 8.8 lbs. – Aquarium Substrate for Strong Plant Growth, Supports Neutral to Slightly Acidic pHPromotes Robust Plant Growth: Stratum fosters vigorous plant development by facilitating easy root penetration and nutrient absorption, aiding in the acquisition of vital nutrients essential for growth Facilitates Rapid and Beneficial Colonization: Its porous structure enables swift colonization of beneficial nitrifying organisms, fostering a healthy aquatic environment crucial for the well being of aquarium inhabitants Maintains Optimal pH Levels: