[vistech]

Are the 4stage ro systems on ebay any good

[Bungle]

Give us more of a clue of what you’re looking at, it’s like asking if the ladders on eBay are any good.

[Spruce]

Speak to Doug at daqua.co.uk.
His r/os are built with superior components, unlike the cheap eBay ones.

A cheap r/o  can turn out to be more expensive in the long run. Cheap Chinese membranes aren't as efficient as USA manufactured ones are so your initial saving are negated by the extra cost of resin to polish the pure off to zero.

Cheap r/os are ok for coffee machines, drinking water and aquatics but not window cleaning as we demand water filtered to much higher standards.

[H2GoKent]

The same is true of carbon pre-filters I bought some years ago when I was first purifying and they dumped into my RO ruining my membranes, talk to someone who knows what they are doing and buy from someone who you can go back to with any issues, worth paying a little more for that I think