you'll find the production will go up if you switch that carbon block out to a GAC filter, higher flow. carbon blocks on well water tend to plug up very fast, it's the organics in the well water, they find a home in a carbon block filter and restrect the flow down to almost zero.
if you had a inline PSI gauge you could see the PSI before the carbon and after, with the pre and post filters being changed every 6-8 months the membraine should last you around 3 years.