Add an airstone to your bucket that you let water sit out in, and consider a fish tank filter that accepts loose activated charcoal to run that water through recirculating for a couple days to reduce chloramine levels.

I found this about chloramine removal at home, and the rest of the article is a good explanation of the chemical and its use:

Drinking Water: Chloramines Water Disinfection in Omaha Metropolitan Utilities District , NF02-505

Chloramine Removal
Many water treatment techniques and equipment are used to alter and improve the quality of water. Several commonly used ones are not effective in removing chloramines. Worth noting are reverse osmosis and water softening units, neither of which effectively remove chloramines. In addition, boiling water does not effectively remove chloramines. And, unlike chlorine which dissipates when water sits for a few days, chloramines may take weeks to disappear. While sunlight and aeration help remove chloramines from water, allowing water to sit is not a reliable method of chloramine removal.
Two effective methods for removing chloramines include using a chemical to neutralize chloramine or using a granular activated carbon filter. Most pet stores sell chemicals for dechloraminating water and can provide use recommendations. Remember that chemicals that remove only chlorine will not remove chloramines. When using a carbon filter, ensure that it contains high quality granular activated carbon. Carbon filters should be operated at a slow rate to allow sufficient contact time for effective chloramine removal. Testing the treated water will help determine the optimum filtration rate. Filters must be monitored carefully to determine when the carbon media has reached the end of its useful life and needs to be changed. Manufacturers often indicate the maximum number of gallons that can be filtered before the filter is renewed. Check with the supplier for proper operation of equipment for chloramine removal.
A carbon filter also will remove chlorine, hydrogen sulfide, organics, THMs, some pesticides, and radon if present in the water. Unserviced or improperly serviced equipment may deliver surges of water with high levels of some of these contaminants. As the owner or user of a home water treatment device, it is your responsibility to ensure proper operation through monitoring, maintenance, and service.
stinkyattic Reviewed by stinkyattic on . Soil Runoff pH, Flushing to correct lockouts- Why and how to do it! This is a common question that comes up when troubleshooting, so I thought I'd post up a little summin summin. Why do you want to know your runoff pH? Simple- it's an indication of how your water, fertilizer, and grow medium are interacting chemically. There are 3 measurements that are important to know when you are caring for plants growing in a soil or soilless medium. The first is the pH of your source water. Next is the pH of your nutrient solution after the fertilizers and Rating: 5