Originally Posted by
SCSInet
http:///forum/post/2592064
All it is is a DeIonization filter.
It performs chemical filtration, but it won't remove things like solids in the water.
The thing about these things is that they eat cartridges for breakfast... A $20 cartridge may make about 50 gallons or so before it exhausts and you need to replace it. An RO unit, on the other hand, has a membrane that may cost $100, but it makes 20,000+ gallons of water. RO units also have a DI cartridge as well, but because the water that goes through them has been already passed through 3 stages of filtration using far cheaper and longer lasting cartriges, you get more like 400 gallons out of a DI cartridge for those.
So although RO units are expensive, their operational costs are insanely lower.
They will actually remove solids. The real trouble is that they are designed to remove extremely small particles, which means that they also remove everything bigger. As a result, you are absolutely right that they wear out quickly.
Still, they are a cheap near-term solution...even if you'd save money within a few months. by investing in an RO or (better) RO/DI filter.