Yes... b'cos most of the LFS sells aquarium for non-planted tank...

And also when given a preference.... based on experiment, plants will prefer amonium NH4 than nitrite or nitrate...

I learn a lot about what is going on inside the tank ( rather than guessing what went wrong ) from the book I mention "Ecology of the Planted Aquarium".

There are also many way the plants can take up the Carbon from the CO2.

Stan