I'm going to try the fishless cycling. Your pinned instructions state that I should add ammonia to raise the level to 5 to 6 ppm. How do I calculate how much ammonia to add (in drops or tsp) to get there. I don't want to do a series of trial and error tests. I know .001 grams/liter = 1 ppm. But how do you measure grams of ammonia. Anyone know the weight of pure ammonia?