Prime water conditioner is one of the best products for stretching your dollar. It is very concentrated much more so than other conditioners but lacks things like buffers and stress coats.
Use 1 capful (5 mL) for each 200 L (50 US gallons) of new water. For smaller volumes, please note each cap thread is approximately 1 mL. May be added to aquarium directly, but better if added to new water first. If adding directly to aquarium, base dose on aquarium volume. Sulfur odor is normal. For exceptionally high chloramine concentrations, a double dose may be used safely. To detoxify nitrite in an emergency, up to 5 times normal dose may be used. If temperature is > 30 °C (86 °F) and chlorine or ammonia levels are low, use a half dose.