i was wondering dose anyone know how to tell if my tap water is treated with chloramine or chlorine? I have starting using Nutrafin as a water treatment and it gives 2 dose rates for the above. at the moment i just us the higher rate but as its twice as much as the chlorine dose i could be making a big saving.

Phone your water company, they will tell you. I believe that most water companies now use chloramine rather than chlorine.

If you are in the UK, while you are on the phone, ask them to come round and test your water, there is no charge for this service

My water company has a website that details water chemistry every so often. It's helpful.