how many grams of ammonium chloride are needed to raise the ammonia level 5 ppm in a 300 gallon system?

I keep getting 2 different answers depending upon how I work the question.

Idk if it's 5.6775 grams of NH4Cl or 16.82811 grams of NH4Cl since it takes 2.964 units of NH4CL to equal a 100% Ammonium solution