Reverse Osmosis Systems
Reverse osmosis is so “good” at removing minerals, such as calcium, from the water that it over-does it. It makes the water too void of minerals for healthy drinking. A Reverse osmosis system is a combination of filters and membranes designed to remove sediment, chemicals, heavy metals, dissolved solids, calcium, sodium, living organisms, and just about anything from the water. It removes so much from the water that it is not healthy to drink this water unless sufficient minerals are added back into it.
Reverse osmosis, RO, forces water through pores in a membrane that are 100 times smaller than the eye can see. The water goes in one side of the membrane with full water pressure and then just drips out the other side. This process takes time, and so a storage tank is usually part of the RO system. Carbon and sediment filters are usually part of an RO system. After being stored in a tank with a rubber membrane, the rubber taste is usually removed with an additional carbon filter. Because the water in an RO system flows through the carbon filters much more slowly than under normal circumstances, it will remove some [but not all] of elements that active carbon usually wouldn’t be relied on to remove [such as fluoride and Chromium-6]. There is a good amount of waste-water produced with an RO system, and so it is highly unusual to use such a system with anything other than drinking or cooking water.
We don't particularly recommend reverse osmosis, because the better water filters will leave all of the healthy minerals and electrolytes in the water and reverse osmosis removes them. The only real reasons we ever recommend reverse osmosis would be to 1) remove sodium if you use a whole-house softener; and 2) remove calcium if your water is excessively hard. In all cases when you use reverse osmosis machine, you should add into your line a filter which will remineralize the water in order to stabilize it, add back in the healthy electrolytes you just removed, and balance the pH of it.
Some reverse osmosis systems will come with re-mineralizing filters that add calcium back into the RO water. If you want or need to use reverse osmosis with a water ionizer, we recommend and sell this one: Reverse Osmosis Remineralizer System. It has the right specs to work well with most water ionizers, although other RO systems can be usually made to work if they have sufficient pressure and a big enough water storage tank. Check with us if you're unsure if it will work with your water ionizer. There is a trick to adding remineralizer filters into a reverse osmosis system, i.e.,you need to know the best place to put them.
Here's a blog post about adding remineralizer filters into a reverse osmosis system.
Partial list of what RO systems will remove from water:
Dichlorocetic Acid
Nitrates
Nitrites
Chromium [ex., Hexavalent 6]
Cysts/Bacteria
Lead & Heavy Metals
Arsenic
Fluoride [some, not all]
Chlorine [some, not all]
Trihalomethanes [some, not all]
Calcium
Magnesium
Potassium
Sodium
Volatile Organic Chemicals [some, not all]
RODI Systems
RODI refers to reverse osmosis and de-ionization. Reverse osmosis is where the water is forced through a membrane which has tiny holes. It sifts the "impurities" out. If a mineral is smaller than the holes of an RO membrane, such as Fluoride, then it can't be fully removed using the RO process alone. DI stands for de-ionized. RODI uses RO first, then goes one step further by passing the water through a bed of resin, which removes the rest of the minerals the RO didn't remove. RODI is unsafe for drinking. Water wants minerals, and to make it void of all minerals is dangerous for drinking. If RODI water circulated inside your body it would want to absorb the healthy minerals from your bones/joints/etc.