Fluval Plant Gro+ Micro Nutrients for Planted Aquariums is a concentrated liquid fertilizer that supplies essential trace elements needed for healthy freshwater plant growth. It contains key micronutrients like iron, manganese, boron and others that may be lacking in aquarium water. Regular use of this 4 oz supplement promotes vibrant, lush plant development and helps prevent deficiencies in planted aquariums without significantly affecting water parameters. Available in Multiple Sizes