This is my second under sink RO system that I have purchased from Crystal Quest. The first one was awesome and lasted 2.5 years before I started having problems with the tank keeping pressure (I believe the bladder ruptured). I replaced the tank, but then started a remodel on my kitchen that took almost a year to complete myself. I originally kept the old RO system to re-use, but because it took so long to complete the remodel we decided to buy a new system rather than cleaning out the old system and buying replacement filters. This time around I had the chemist at Crystal Quest to look at my cities water report to see if we needed to add anything else......It turned out that my water supply is at EPA maximums for several categories so we added a fluoride filter and nitrate filter as PRE-filters before the RO. Hopefully this will help the RO last longer. Also I would always recommend getting a pump system because the first RO filter I got from Crystal Quest would not work with the water pressure that I have from the city. It would make a sip per day, so I had to add a pump to the first system. And my second piece of advice is to get the remineralizer filter as a post filter......it makes the water taste really refreshing. There are other filter manufacturers out there, but I consider these to be the "Cadillac" of them all. I will always have one wherever I live and I am a contractor so I recommend them to my clients all the time. Disclaimer, I am NOT being compensated by Crystal Quest.