I have no clue what Tropica puts into their plant pots. What I do know is I have been using Tropica ferts for over 20 years and highly recommend them. I started with "MasterGrow" which then morphed into "Plant Nutrition Liquid". Then in 2013 they went to the current two ferts system. I used to buy the 5 liters sizes, but those have become impossible to find. I have both the Specialized and Premium today. Depending on the plant and fish load, I use one or the other and occasionally I mix them.