It is a good idea to update your system because parts can wear out and the technology is also getting better and better. Some manufacturers recommend changing the system every 5-10 years.
Here are a couple good options for a new RO system. RO water is the best because of the RO membrane which reduces dissolved solids such as nitrates, sodium, barium, etc.
http://www.waterfilters.net/Good-Water-Warehouse/Reverse-Osmosis/systems/PuROTwist-4000.htm http://www.waterfilters.net/Good-Water-Warehouse/Reverse-Osmosis/systems/PuROTwist-3000.htm
Thank you,
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