This 2 oz (60 ml) bottle of reagent grade ammonium chloride for use when fishless cycling.
The concentration is 40 mg/ml of total ammonia-nitrogen (TAN).
Dose 4 drop per gallon of aquarium water.
(NOTE: this was changed in Nov 2016. If your bottle says add 1 drop per gallon add 1 drop per gallon but if your bottle says add 4 drops per gallon add 4 drops per gallon).
1 drop equals 0.05 ml so this bottle will dose 1,200 gallons of water one time.
Generally during a fishless cycle one needs to add ammonium chloride to their tank 3 or 4 times so this bottle is enough ammonia to cycle aquariums up to 100 gallons (378 lites).
1 teaspoon equals about 5 ml which is 100 drops.
1 tablespoon equals almost 15 ml which is 300 drops
1 ounce equals 29.5 ml equals 590 drops