Here's the deal. Regardless of what filters are put in a whole house system there are limitations of what we can remove, it’s not our filters, but limitations as per technology, water pressure and water flow. So if you want to know, here’s what you need to know.
A common Australian shower uses around 10 litres per minute, so one common bucket of water per minute. Thus two showers and a dishwasher needs 25 litres per minute to operate, but also needs the water pressure to be able to supply the 25 liters per minute and more as extra sources of water are being used, washing machines etc.
So a whole-house filter is limited, because it needs to flow fast, not block too much pressure, and also last a long time, so you’re not changing filters every six months. So at this fast flow rate we are not able to remove some nasty contaminants. Thus, we’re forced to move under the sink, where we don’t need so much water flow as it's just for drinking.
The difference is, this RO system makes water at like 200mls per minute. So now we can slow the water flow right down and filter the water at a very low micron level like 0.0005 micron.
Thus the technology of filters under the sink, allows for different technologies that removes the finer contaminants making Ultrapure - bottled quality water for you at home.
Take a look at the twin, Toxic Contaminant Removal Reverse Osmosis water filtration system. The TCR RO is purposely made to work in with this ULTRAPURE whole home water filtration system. Pure drinking water is the ultimate way to live.