Under sink water filter systems need to be connected to pipes underneath the sink to ensure that the water is properly cleaned and filtered. As such, compared to other water filtration systems, under sink water filter systems can be a bit more complicated to install because of the need to connect them to a water pipe. Still, it must be pointed out that these under sink water filter systems are extremely easy to maintain after the initial installation. Since under sink water filter systems utilize a filtration process that needs two steps, they ultimately end up being less effective than pitcher type filter systems. Still, their filtration capability surpasses that of refrigeration filtration systems.