I have a friend living in an area where the water is quite high in TDS ...around 4000 ppm...is this considered brackish water ?
Is it possible for him to install an RO unit for drinking water ? (he needs about 20 liters per day)...if so ,what kind of system would be suitable for him ? He doen't really care if he has to change membranes every 6-8 months but he needs to be sure that the RO water will be clean enough to drink it.
Are the standard domestic systems suitable for these applications ? or the standard TW30 membranes will not last even a day ?