Chemical Taste with new inserts

Hi,

I recently installed new filter inserts into 2 different in line systems--one for me, one for my Mom. Both systems are the same, they consist of 2 housings--both accepting standard 10" filter cartridges.

I put 1 new foam and 1 new carbon cartridge (generic) in each system (see example.) They both are putting out a chemical taste despite running the water for over an hour. However, on my Mom's system the chemical taste is more pronounced.

I've just been drinking the tap water instead, its so bad.

What is up with this?

Thanks!
js