Chlorine has long been used for treating water to remove any bacteria that may be present, thereby making it safe to use and consume. The most common way to remove the chlorine in the past was to simply let the water sit out and it was commonly believed that 24 hours, or overnight, was a sufficient amount of time to let it evaporate. Ten years ago, that may have been true but times have changed. Municipalities no longer use only chlorine to treat water, instead turning to a different chemical: chloramines.
Chloramine is a combination of chlorine and ammonia. You cannot simply let the water sit out anymore. Chloramines do not evaporate into the air, which is one of the reasons treatment facilities started using it. Chlorine’s ability to break down when exposed to the air and sun, even motion. Chloramines are harder to get rid of.
Most water filtration systems do not remove chloramines. Because of that, when using this water for your garden, there will eventually be a chemical build up that can be devastating. Rain water is the best solution. Been having troubles in the garden you can’t explain? Does your municipality use chloramine to treat the water?