A refrigerator can get its water from its own internal cartridge or from an under sink reverse osmosis system, and both are reasonable. The choice is less about water quality, where the membrane wins comfortably, than about what each arrangement asks of the household in installation, capacity and ongoing cost.
What the membrane feed gives you
Clear ice rather than cloudy, because dissolved minerals and air are what make ice opaque, and ice that carries no taste into a drink. Water from the dispenser identical to what comes out of the kitchen RO tap rather than water through a small carbon cartridge. And, in most cases, the end of buying fridge cartridges, since the appliance's own filter can be removed and its bypass plug fitted. That last saving is often what tips the decision.
What it asks in return
A tubing run from the system to the appliance, kept short and free of tight bends so pressure at the dispenser stays usable. Some tank capacity, because an ice maker refills in bursts and can empty a small storage tank, leaving the RO tap trickling while it recovers. And a decision about the appliance's own filter: keeping it as a second stage slows the dispenser noticeably, while removing it needs the bypass plug and, on some models, defeats an electronic check that expects a cartridge.
When the built in cartridge is the better answer
If there is no reverse osmosis system and no plan for one, a fridge cartridge is a perfectly sensible way to improve taste at that appliance for a small annual cost. If the appliance authenticates its cartridge electronically and will not run without one, feeding it from a membrane means paying for both. And if the run from the kitchen to the fridge is long or awkward, the pressure drop can make the dispenser disappointing, which is worse than the cartridge it replaced.
Doing it well
Size the system for the extra demand before running any tubing: a larger tank, a permeate pump or a higher production membrane all help. Fit a shut off valve at the tee so the fridge can be isolated without shutting the system down. Discard the first several batches of ice and the first litres from the dispenser after connecting. And keep the system's prefilter schedule, because everything the fridge dispenses now depends on it. Our whole house RO guide covers the larger scale question.
Questions people ask about reverse osmosis fridge
Does RO water make better ice?
Clearer ice that carries no taste into a drink, since dissolved minerals and air are what make ice cloudy and flavoured.
Can I remove the fridge's own filter?
Usually, with the manufacturer's bypass plug, though some appliances authenticate the cartridge electronically and object.
Why does my RO tap trickle after connecting the fridge?
The ice maker draws in bursts and empties a small tank. A larger tank, a permeate pump or a higher production membrane fixes it.
When is the built in cartridge the better choice?
Where there is no RO system, where the appliance requires its own cartridge, or where the tubing run would be long and awkward.