Why does larger chloramine filter last so much longer?

[Harry Muscle]

I've been doing research on chloramine removing filters and I'm trying to understand why increasing the filter size increases its capacity disproportionately. For example, the Pentek ChlorPlus 10" filter can treat 1000G with a flow rate of 1gpm. If we double the filter size to 20" the filter can now treat 5000G with the same flow rate. Doubling the amount of fitter material results in 5x increase in capacity. Why would that be the case?

Thanks,
Harry

 

[zachfishman]

It's all about contact time. More contact time = more filtering efficiency. This is why carbon cartridge ratings are accompanied by gpm values. A 20"x2.5" cartridge has twice the carbon surface area than a 10"x2.5" cartridge. Water passing through a 20x2.5 cartridge at 1gpm is traveling half as fast through the carbon compared to 1gpm through a 10x2.5 cartridge. This is why at 1gpm the 20x2.5 Chlorplus is rated to handle 5000G compared to the 10x2.5 at 1000G for the same flow rate (when you would expect 2000G vs 1000G).

 

[tkeracer619]

^^What he said.

I got tired of the small filters and use the 20BB Chlorplus. I have made a ton of water on one cart. It has been one of the best investments I have made to date. A 20BB Chlorplus weighs like 20lbs :lol: