Tds up from 4 to 6

[Spare time]

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.

 

[Quietman]

It can fluctuate a bit...mines varies between 12 and 20 something from the RO. Carbon filters are good for a year usually (but can be less). Pressure variations can alter as well.