After having one of those undersink systems, I can say they work, the water is very pure coming out, only issue being that it’s basically pure water - no minerals, no anything - some issues there with actual hydration since drinking pure water can kill you - look up hyponatremia.
edit: might not be the case - see reply
The principle is the same as for the more expensive systems, what you don’t get is
potentially an UV inline lamp to sanitize stuff
a pump to increase the pressure and increase efficiency/speed
maybe a storage tank (some cheaper models have like a 1-2 gallon storage tank)
not sure about this one but more expensive membranes might have a better removal rating - mine said 95% I think
If you have around 45 psi of water pressure on your tap, it’s good enough, but don’t expect to be bathing in the stuff, it takes quite a long time to get usable quantities and I think you get 1L RO water to 4-5 L ‘waste’ water. Higher pressure - higher efficiency and speed but check the pressures the membrane is rated for. Also if your water is chlorinated you need some activated charcoal pre-filters because chlorine harms the membrane.
Maintenance should also be done regularly to change prefilters once every 3 months and the membrane once every 9-12 months. And it can get slightly messy on cheaper models.
ACUTE effects of drinking distilled water
The idea behind the myth that distilled water is harmful is that its low osmolality (“tonicity”) could dangerously decrease the blood osmolality, which is normally: 285-295 mmol/kg. But distilled water has only slightly lower osmolality (0 mmol/kg) than tap water (~3 mmol/kg) (SGSM.ch, Table 2), so if drinking appropriate amounts of tap water does not significantly lower blood osmolality, distilled water also shouldn’t.
The difference between tap and 100% pure water is so slight that it’ll never cause hyponatremia. What WILL cause hyponatremia is drinking way, WAY too much water in a short span of time. That’ll dilute your blood (hyponatremia) from ions that you need as your kidneys desperately try to get rid of all the water. This is entirely mitigated by eating foods around the same time that are not entirely deficient in minerals like salt (pretty much all foods).
After having one of those undersink systems, I can say they work, the water is very pure coming out, only issue being that it’s basically pure water - no minerals, no anything -
some issues there with actual hydration since drinking pure water can kill you - look up hyponatremia.edit: might not be the case - see reply
The principle is the same as for the more expensive systems, what you don’t get is
If you have around 45 psi of water pressure on your tap, it’s good enough, but don’t expect to be bathing in the stuff, it takes quite a long time to get usable quantities and I think you get 1L RO water to 4-5 L ‘waste’ water. Higher pressure - higher efficiency and speed but check the pressures the membrane is rated for. Also if your water is chlorinated you need some activated charcoal pre-filters because chlorine harms the membrane.
Maintenance should also be done regularly to change prefilters once every 3 months and the membrane once every 9-12 months. And it can get slightly messy on cheaper models.
This is a myth. You cannot be harmed from pure water, even distilled water. Lab-pure molecular water tastes like shit, anyways.
https://medicalsciences.stackexchange.com/questions/20837/can-drinking-ultra-pure-water-be-dangerous
The difference between tap and 100% pure water is so slight that it’ll never cause hyponatremia. What WILL cause hyponatremia is drinking way, WAY too much water in a short span of time. That’ll dilute your blood (hyponatremia) from ions that you need as your kidneys desperately try to get rid of all the water. This is entirely mitigated by eating foods around the same time that are not entirely deficient in minerals like salt (pretty much all foods).