I moved to a new house and found a 10" big blue water filter installed under the kitchen sink, of the type that would normally be whole-house. The water tastes off and I am assuming that the cartridge needs replacing, since it looks pretty filthy and I am fairly sure it has not been changed in several years.
I found these instructions for changing the cartridge. However, there seem to be a hundred types of replacement cartridges. I tried to look at various DIY and plumbing sites, but I still have no idea what type of cartridge is appropriate for filtering New York City tap water, or even whether this is a bad idea and I should replace the whole thing with a standard under-sink filter. Pleated? String? How many microns? Etc. It's all Greek to me, so any advice is greatly appreciated.