These filter are the best you can buy in this category. The question is how many do you have to use to keep your water where you want it i.e. 0 or close to it. In the interest of full disclosure Zero Water should provide approximate filter life for your water's TDS content which could provide an approximation of how long a filter might last. Of course, not using plastic and carrying jugs or distilloed water from the market is a plus but at some point doing that might be economical enough to have it make sense. Also, I am pleased that larger quantities are now available; understanding why they weren't would have been useful to long time customer who buys in quantity.
The water is very clean and drinkable. I use it for cooking and also for my pets. My dog Cody and my two parakeets, Sydney and Rudy. We also drink it as well. In Florida the water has been very bad for years. However, it is just as bad in other states. I highly recommend the largest glass canister and the zero waters filters. Make sure you have the TDS, total dissolved solid water reader! Use it to check your filtered water periodically to make sure the water level is at 0 for the cleanest water you can get! Also the reader/meter will tell you when You need to add a new filter.