What the percentage reduction of arsenic is for your filter?

Can you tell me what the percentage reduction of arsenic is for your filter? I also have another question. Does the pH of the water affect the percentage of arsenic reduction? Our water, which is from a private well, has a pH of 7.6 and arsenic content of 0.18 mg/l. The arsenic is really the only concern in terms of what we need to filter for. It would appear that Doulton's Model IP300PSCA-5 filter would be the best for our situation. Would you agree?
You are absolute correct as far IP300PSCA-5 model is ideal for your water conditions. The pH is surprisingly low for well water, almost neutral however your arsenic level is high compare to EPA maximum allowable of 0.010 mg./L. The arsenic cartridge will remove all of the arsenic to none detectable level for at least first 350 gallons.