[PmNuc8689]

Good evening,
I would like to know if anyone can help me learn about how long chloramine persists in aerated tap water.  Here is my situation: I keep delicate tropical fish.  I fill several 50-gallon containers with tap water and let it cure for about 2 weeks before introducing the water into my aquariums. During the cure time, the water is vigorously aerated and heated to about 79 degrees F (26 C).  I realize the chlorine burns off within hours but what about the ammonia the water company adds.  Some hobbyists suggest activated carbon might eliminate the chloramine.  I would rather not add 'water conditioner' chemicals if unnecessary.
Many thanks!

[Borek]

Never heard about ammonia being added to water, do you mean the one being product of the chloramine hydrolysis?

If so, I wouldn't care. Ammonia is part of the nitrogen cycle of water in the tanks so its presence is inevitable, its recycling is part of the ecology of the healthy tank. Additional traces from the chloramine will be recycled as well.

[PmNuc8689]

Yes, they have been adding ammonia to our drinking water for many years.  Here is a quote from the EPA site about chloramines: "Are most commonly formed when ammonia is added to chlorine to treat drinking water. Provide longer-lasting disinfection as the water moves through pipes to consumers."
I understand about ammonia and the nitrogen cycle in an aquarium.  My question is how long chloramines remain in water that is placed into a container (not aquarium with filtration) just a container that is aerated?  For example, someone fills a two-gallon jug with tap water and lets it sit for a few days.  I understand how the chlorine dissipates but what about the ammonia?  How long will the ammonia last in the container? 

[Borek]

Yes, they have been adding ammonia to our drinking water for many years.  Here is a quote from the EPA site about chloramines: "Are most commonly formed when ammonia is added to chlorine to treat drinking water. Provide longer-lasting disinfection as the water moves through pipes to consumers."

This wording is ambiguous, sounds to me like "ammonia added to chlorine to produce chloramine used to treat the water", not like "adding ammonia directly to water". But I am not going to argue, we both agree final effect is that ammonia is present in water.

My question is how long chloramines remain in water that is placed into a container (not aquarium with filtration) just a container that is aerated?  For example, someone fills a two-gallon jug with tap water and lets it sit for a few days.  I understand how the chlorine dissipates but what about the ammonia?  How long will the ammonia last in the container?

Ammonia is lost in a similar way, although - as is easily reacts with water and has much higher solubility - probably much slower. But the speed at which it happens is one of things that nobody will be able to reasonably estimate, as they depend on way too many factors. Experiment is the simplest way.