A while back I bought some cheap activated carbon block filters which actually made our water taste a lot worse. I think it was the taste of iodine. Needless to say, they got rid of them. I bought them because they were reasonably priced and the price was between the most expensive and cheapest filters. This can be the case if you get what you pay for. They improve the taste of our water somewhat, but not as much as the expensive filters I've used.