Flora Viv P is a high quality, concentrated, bio-available phosphorus supplement for freshwater planted aquariums. It is designed to provide phosphorus, a critical key to the uptake of other nutrients in all aquatic plants. Phosphorus deficiency often causes stunted growth and very dark green (almost blue or purple coloration) instead of normal green. Use Flora Viv first, to provide a wide range of plant nutrients, and then use then use Flora Viv P, this product, to supplement phosphorus, if necessary (determined by testing!). Flora Viv products contain no toxic polycycloglutaracetal or glutaraldehyde. Do not overdose this product! It is recommended that the hobbyist maintain an N:P ratio of 10 to 20 parts nitrogen to 1 to one part phosphorus. This ratio will provide steady plant growth, while, to have a higher ratio may cause unwanted algae growth. Simultaneous use of Bacter Gen F to establish and sustain growth of proper microorganisms and recycle aquarium nutrients will greatly benefit all plants. The use of Flora Viv Prolifera will provide additional carbon for heavily planted aquariums.