The DuPure Pure Blue and Ultra Pur reverse osmosis systems use proprietary filters. As such, the replacment filters are very expensive.
Replace your system with a PuROTwist Manifold & Filter kit. You can keep your existing faucet, tank and tubing. Then purchase yearly replacement filters for nearly half the price of your DuPure replacement filters!
DuPure reverse osmosis set - 3 replacement filters
1-Year Filter Replacement Kit
for PuROTwist 3000 with 50 GPD TFC Reverse Osmosis System