This is a somewhat complicated question which depends on several factors; the biggest is your overall water chemistry. I cannot stress enough that trying to select a filtration solution without knowing all of the related chemistry is like throwing darts blindfolded. Sure you might get lucky, but chances are you’re not going to get the results you expect. Other important considerations include the presence of sulfur or bacteria, the amount of iron, the pH, the flow rate and daily water requirements. Once you look at the whole picture then you can select the appropriate equipment to meet your needs. The best answer to this question is to select the simplest system possible that meets your needs.