Reverse Osmosis do and dont

im looking in to getting a do/di unit does it matter on the STAGEs
i want to get a good one but i dont know anything about ro/di units.
some info would be helpful.
thanks

 

Click on FILTERS in the forums section, you'll find lots of info and opinions.

 

The number of stages is not nearly as important as what those stages contain. The ebay vendors started the big "stages" war when they started selling low end drinking water systems with additional "stages" to make they sound like the best thing since sliced bread. In reality though they didn't improve anything, in many cases they made them the same or worse. Just because you add an additional granular carbon in front of a crabon block does not improve its performance, it actualy hurts it because the granular carbon is good for a maximum of about 300 total gallons of water, thats 60 good RO or RO/DI and 240 waste gallons, then turns to dust and fould or plugs the carbon block. Adding two dinky horizontal DI "stages" the claiming the additional length end to end is what you need is bunk. A single 20 oz vertical DI that fills from the bottom up so all resin and water come into contact with each other will work better every time. Horizontals channel and short circuit so wate rbypass the resin, its the path of least resistance we hear about all the time. Same with the add on carbon taste and odor filter, it actually ADDS TDS back into the treated water you jusy worked hard to purify.
There are many more issues with teh low end systems but suffice to say you want and need 3 stages for a good RO and 4 stages for a good RO/DI, no more and no less unless you have very specific water problems and needs.
A couple very good choices that run about $150-$170 are the ProPlus found here:
SpectraPure Customer Appreciation SALE! 20% - 50% off

or the 75 GPD Premium found here:
http://www.buckeyefieldsupply.com/showproducts.asp?Category=168&Sub=166

Both include TDS meters, inline pressure gauges, hose bib thread adapters, name brand RO membranes, high quality filters and in the case of the ProPlus the membranes are tested and the DI resin custom mixed for optimum performance.