A few things to beware of when looking at the "budget" RO
units. First, don't be misled by the one claiming to have 5 or 6 stages. Usually, this means that it comes with an inline post DI
carbon cartridge which is not necessary. The 6 stage units often have two sediment filters...again, in most situations, this is of no benefit. If you're on well water, you might benefit from dual sediment carts. I use a 10 mic followed by a 1 mic because my well can get a little muddy at times. For city/county water, it's not needed. Another thing I've seen is that some of the units will have an "inline" DI
cartridge. These are smaller than the regular DI
cart and do not last as long. They are nearly as expensive to replace as the full size carts. All you really need is 1 sediment, 1 carbon, RO
cartridge. Most of these units will not come with pressure gauges or TDS
meters either. I'm not trying to talk you out of buying one...just pointing out some of the things manufacturers do to cut costs or make thier unit seem better than it really is. Take a look at the Aqua FX units. These are top of the line, no nonsense units. Even if you don't want to buy one of their units, I would suggest using them as a comparison for any unit you're looking at.