because one of the leading lights of the coffee world has said the water filtration systems like Claris are not up to his exceptional standards and you really need an RO system to run with the big dogs it seems that everyone has accepted this proclamation as fact
it is utter nonsense, and in the circumstances one can only wonder if ‘RO’ might stand for ‘rectal output’
ANY filter in ANY system in the world will go skank if you don’t replace it at the specified interval, including for example the fuel filter in your car or motorbike
A time interval is meaningless as it does not account for the number of litres that the filter has treated
The only way to go is to instal a volumetric meter that allows you to set an alarm to ring when the filter has treated the number of litres of water that you have calculated as the service life of the filter
You also need to match the size of the filter to your usage as filters will also go skank with time, even if they have not treated the volume of water that has been calculated as their service life
i.e. the manufacturer will state a time interval that the filter must be replaced within, regardless of the number of litres treated
In other words don’t go and buy an XXL Claris which is rated to treat thousands of litres of water if you pull a couple of shots a week, in fact don’t even connect your machine to a water filtration and softening system; use a suitable bottled water like Volvic, or a filter-softener that fits into the tank of your machine
It is true that if you live in an area with very hard water, like many parts of London for example, that the service volume of the filter is dramatically reduced, perhaps by a factor as great as 4 or even 5. This is not the same as saying it is not fit for purpose in my view
Reverse osmosis (RO) systems do give you the ability to strip everything out of your water then reintroduce the elements you desire and in the proportions you choose (assuming the person operating it knows what they are doing), but they are not a necessary condition for making world class coffee
I would respectfully suggest that an RO system will go just as skank as a filter system if it is not adequately maintained