What does NSF/ANSI 58 mean in practice?
RO performance and any additional claims, flow, recovery or production apply to the certified configuration and test conditions.
When does it matter?
The number 58 does not mean every system removes all contaminants or performs identically at different temperature and pressure.
Which solutions are related to it?
Check the official model listing, claims, TDS performance, production, recovery and required service of every stage.