Some notes:
1. Standard Activated charcoal filters will NOT remove chloramines. Even for filters of the right type, the recommended contact time of the water with the charcoal is a minimum of 45s. That is a pretty slow delivery rate. Even THEN, the filter will only remove the chlorine half of the molecule, and will not remove amonia half. So, now you have amonia in your water. I don't know if amonia at that concentration will have an effect or not.
The size of carbon filter required to filter choramines from water at a rate of 1 gallons per minute is 110 lbs.
http://ndt.oxfordjournals.org/content/14/11/2579.full
2. Camden tables come in two different chemical forms: Sodium bisulfite, and Potasium-Metabisulfite. Each form will leave the cation in solution after the sulfite has done its thing. Thus, you will end up with either Sodium or Potassium in your beer. Potasium is flavor neutral at these concentrations, but sodium is definately NOT. Be sure you are buying POTASSIUM Meta-Bisulfite (POTMETA). You can buy this in granular form rather than tablet form, as well. then you can dose by the gram instead of fractions of a tablet.
3. Ascorbic acid can also be used to remove chloramines. 1000 mg tablet of vitamin C treats 40 gallons of water. So, a quarter tablet would treat 10 gallons of water. NOTE: the half-life is 4 minutes. So, for each 4 minutes that it sits, half of the remaining chloramines will be eliminated. So, you need to let it sit for 20 minutes or so to have removed most of the chloramine. That's only 8ppm, so its pretty safe for brew flavor. Plus, its a lot easier to find (you can get it at the grocery or drug store), than POTMETA.