Depends on the type / concentration of your ammonia. Also, liquid ammonia decreases in concentration over time, so age matters. IMO, you're just going to have to test it.
FWIW, in a 2-gallon tank, with slightly less than 2 gallons of water, I got the ammonia up to .5ppm by taking a 1/8 teaspoon measuring spoon (about the dimensions of a popcicle stick), dipping it into the ammonia (not filling the spoon, dipping it) and then swishing the spoon around in the water. The ammonia was from Ace Hardware and is supposedly 10% ammonia.
Liz