ro/water

I guess it all depends on what you are trying to accomplish. Are you trying to get RO water or just pure filtered water? Pure filtered water is basically just heavily filtered through micron filters and carbon. Most food service and whole house systems use this type of filtration to "improve" water quality. RO water on the other hand actually makes pure water. It removes all kinds of metals, nitrates, and other impurities. If you add deionization to the mix, it will remove cholarmine as well. Basically if you are using a complete RO/DI filter, you really don't even need to add water conditioner. I do just for the warm fuzy! Does this help answer your question?

Most RO setups, Like mine have 2 stages, or more...

first there is a prefilter section, there is usually a coarse prefilter to remove sediments, and rust etc.. then a smaller micron filter to remove smaller particles, pollutants and stuff.. and finally a carbon block filter to remove foul oders and taste.

After that the cleaned water travels to the RO membrane, this is the Reverse Osmosis part of the filter, it is only one step... The water is forced through a "roll" of membrane material, with microscopic pores in it, thus filtering it on a microscopic level beyond what the prefilter section is capable of.

Some units then run the RO water through De ionizers that remove any charged ions in the water making it ultra purified...

the magic in an RO system comes from the membrane itself, to get decent membrane that is capable of a decent output per day is tough. Most hardware store units produce about 10-25 gal per day, and most LFS RO systems produce about 30-50. Mine is a 3M (filmtec) membrane that is good for 100GPD. had to get it online.

Output is affected by water pressure, optimum pressure at the membrane is 70-100PSI.. less than that and you will not get alot of water from the system...