How much are merlin membranes, £100?
Merlin from Gardiners is what, £350?
So after 3 years with you buying a membrane once a year, you’ll have spent £550 ish (not including prefilters) on an RO that, contrary to what a person or two think, is not as efficient as a 4040; not even close according to some peoples figures.
4040 membrane on average for most (baring the odd one) seems to last 3 ish years, so its the same costing over 3 years but much more efficient, less resin used as a result.
Same long term costs (ish), ones more efficient than the other, uses less resin, flow adjustable, you can flush to prolong the life of a membrane, can produce more water faster etc etc... and the other isn’t/doesn’t...
I’m no RO expert as I’ve said before, but why do people buy a merlin again? Just so they can ‘save’ a couple of hundred on initial outlay or because they feel compelled to only buy from Gardiners?