Replacing carbon block filters in deionization (Ion Exchange) system annual maintenance
According to a local expert, and the manual...

Both granulated carbon and carbon blocks should be rinsed down for ~5 bed depths (enough water to fill and empty the sump or tank 5 times).  This is to remove carbon fines which may otherwise make it through the filter and to rinse out any byproducts from the creation of the carbon that would otherwise be taken out by the resin and partially spend it’s capacity. If the tank is large enough*, larger than .25 cb. ft, there will not be any noticeable difference from a 10” carbon cartridge being rinsed into it. The rinsing time is just 5-10 minutes is all.  You may see some cloudiness or bubbles in the water for up to 1-2 weeks but that will rinse out with time.  The bubbles are just a product of how porous the carbon is and it takes some time to rinse all of it out.

*their base model is a .15 cuft