My tap water is not suitable for brewing as is. I normally do 5 gallon batches with Poland Spring. I do have a bottle of Campden tablets.
My extract boil is usually 3 gallons and I top off with 2 gallons of cold water.
If I use 1/4 tablet in my boil will it also remove Chlorine and Chloramine from the entire batch when I add the top off water?
Add the campden tablet into the water you want to declorinate before you use it to brew. Palmer says, the de-clorinization of water using campden tablets is near instantaneous. i have don it with very good results.
yeah, just drop another 1/4 tab into your top up water and let it do its thing while you're boiling the main batch.
1 tablet should be able to treat 20 gallons of water.
I always let it sit overnight.