Why does larger chloramine filter last so much longer?

Harry Muscle · Jan 3, 2017

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

Daniel@R2R · Jan 4, 2017

Good question... #reefsquad

Brew12 · Jan 4, 2017

The 10" filters are 2 1/2" in diameter. The 20" filters are 4 1/2" in diameter. That is what provides the extra filter capacity.

Harry Muscle · Jan 4, 2017

Brew12 said:
The 10" filters are 2 1/2" in diameter. The 20" filters are 4 1/2" in diameter. That is what provides the extra filter capacity.

Actually there are both 2.5" and 4.5" versions of the 20" filters. The 2.5" version of the 20" filter is exactly double yet it lasts 5x longer.

Thanks,
Harry

Brew12 · Jan 4, 2017

Harry Muscle said:
Actually there are both 2.5" and 4.5" versions of the 20" filters. The 2.5" version of the 20" filter is exactly double yet it lasts 5x longer.

Thanks,
Harry

Good call, I missed that. It's very interesting that for Chlorine taste and odor the 20" one has twice the rating as the 10" version which makes sense.

Each size filter has also 2 ratings for chloramine based on flow. Cutting the flow in half makes each filter 2 1/2 times more effective against chloramine. The one thing that is consistent is that the 20" version at 2gpm has the exact same rating as two 10" filters at 1gpm. The slower flow rates must have a large impact on how deeply the chloramine gets absorbed into the media, impacting it's total capacity.

http://waterpurification.pentair.co.../en/310106-chlorpluscartridges-rev-b-my15.pdf