Water purifiers can remove smallest disease causing bacteria that are in the water such as E. coli, Cholera, and Salmonella where this kind of bacteria can get through water filters.
Not only that, water purifiers retains the sweet taste of the fresh water. It removes the foul taste odors of the water and chemicals that is in the water. It also removes microbial contamination. These Purifiers have what water filters have and what is more amazing purifiers are that it retains the mineral and traces of elements in the water which is necessary for your health.
While water filters get rid of the chemicals and it removes or filters the water disinfectant such as chlorine and other chlorine resistant parasites. It also removes the foul odor, taste and some chemicals but this depend on the filtration technology used. Filters cannot eliminate the viruses which are the smallest micro organism only purifier can do that. Now since you know the difference between the purifier and filter, it is now your choice which one you want to be installed in your house.
Under sink purifiers have lots of different sizes with different brands you need to choose. There are also portable water purifier that you can bring anywhere you go. If you want a smaller size of water purifier under your sink to install, there is. Even how small your space under your sink, you can have it. All you have to do is to shop around to find your desired water purifier.
To get the cheaper under sink purifier, all you have to do is to roam around to shop or read this guide about Best Under Sink Water Filter Systems.