There is no mention of Nitrogen or Phosphates, just Potassium and Iron.Without proper fertilization, aquarium plants gradually yellow, drop their leaves and die. Aquarium plants require essential nutrients for vibrant growth. API® ROOT TABS are formulated to supply key nutrients, including iron and potassium and carbon, to help new aquatic plants get off to a vigorous start and to keep established plants flourishing. These nutrients are consumed over time in the aquarium and must be replenished for plants to thrive. Safe for use with tropical fish.
Actually at the back of the packaging it says:Hi iant,
API Root Tabs do not contain any macro nutrients. This is their description of their product:
There is no mention of Nitrogen or Phosphates, just Potassium and Iron.
And here is the MSDS (OSHA Form 20) information on the product, the main ingredients are clay and carbon with 'additives'.
I strongly recommend Seachem Flourish Tabs as a much more balanced tab, it even helped me to grow Pogostemon helferi in a low tech, no CO2 tank.