So my water going into my di resin is usually 3 or 4, but yesterday night it went from 6 to 7. The ro membrane isn't old enough to start having issues, so I was gonna swap the carbon and sediment since I am not sure which is causing is. The pressure hasn't really dropped and I couldn't tell with the chlorine strip if there was any or not. Do you think I should replace the carbon and sediment or is this just a possible range of error in the inline tds meter.