Some vendors offer a one-tank Point-of-Entry system. What are the advantages and disadvantages of a one-tank system compared to the more common two-tank system?

One-tank POE system disadvantages:

• With no back-up/safety tank homeowners are at risk of drinking water with unhealthy levels of arsenic during the period after the arsenic begins to break through the treatment media and before the next testing.

One-tank POE system advantages:

• Cheaper in the short term