Why a sediment filter and not two carbon filters?

[ichthyogeek]

So in a typical 4-stage RODI setup, it's sediment filter->carbon filter->RO membrane->DI filter. If both the sediment filter and the carbon filter have the same micron rating (usually around 5 uM), then, aside from cost, why not just use two carbon filters? Am I missing something?

 

[Sabellafella]

So in a typical 4-stage RODI setup, it's sediment filter->carbon filter->RO membrane->DI filter. If both the sediment filter and the carbon filter have the same micron rating (usually around 5 uM), then, aside from cost, why not just use two carbon filters? Am I missing something?

Its basically a pre-filter so you don't clog the carbon block prematurely. As quickly as my sediment clogs up, I can't even imagine how fast my carbon block would be rendered useless

 

[Tastee]

The carbon filter is serving a different purpose to the sediment filter. It’s job is to remove lots of chemicals, particularly Chlorine and Chloramine. As said above without the Sediment filter to remove large solids it will quickly clog up and dramatically reduce your water production. The sediment filter due to it’s open weave construction can suspend vastly more large solids than the carbon filter can.