The IceCap 5 Micron CTO Carbon Block is a standard second-stage pre-filter cartridge for reverse osmosis and RO/DI systems on chlorinated municipal water. It is positioned after the sediment stage and before the RO membrane, where it removes residual chlorine and organics that a sediment filter alone cannot intercept. Left untreated, chlorine in feed water will degrade and eventually destroy a thin-film composite (TFC) membrane, making a functional carbon block pre-filter a non-optional part of any RO system on city water.
The 10in industry-standard form factor fits the IceCap Smart RODI system as well as virtually every other brand's standard filter housing. This is a CTO (Chlorine, Taste, Odor) carbon block, which treats for chlorinated municipal water. If your water utility uses chloramine rather than chlorine, this cartridge will not provide adequate protection — see the IceCap Chloramine Reducing Carbon Block instead.
Removes chlorine and organics at the second stage of a standard RO pre-filter sequence
5 micron rating blocks fine particulates that pass through a coarser sediment stage
Fits any standard 10in filter housing, including the IceCap Smart RODI system
CTO formulation treats chlorinated municipal water; not rated for chloramine removal
For use with microbiologically safe and adequately disinfected water only
Flush for a minimum of 10-15 minutes before directing output to the RO membrane
Hobbyists on chlorinated municipal water replacing an expired carbon block in an IceCap or compatible RO system
Reef and freshwater aquarium keepers maintaining the pre-filter stage of a multi-stage RO or RO/DI system
Anyone building a new RO system using standard 10in housings who needs a reliable, straightforward carbon block
Confirm your water utility uses chlorine, not chloramine, before buying this cartridge. CTO carbon blocks treat for chlorine. If your municipality has switched to chloramine, this filter will not adequately protect your membrane. Request a water quality report from your utility to confirm.
Always flush for at least 10-15 minutes before use. Carbon fines are released during the first flush. Do not run the output to your RO membrane or aquarium until the initial flush is complete.
Replace on schedule, not on taste or smell. Chlorine removal capacity declines gradually before it becomes detectable. Replace this cartridge at your system's recommended service interval to prevent membrane damage.
Change the sediment and carbon block together. If the sediment pre-filter is clogged or exhausted, it can push particulates toward the carbon block, reducing the carbon block's effective service life. Replacing both at the same time during routine maintenance is the cleaner practice.
The IceCap 5 Micron CTO Carbon Block is a standard second-stage pre-filter cartridge for reverse osmosis and RO/DI systems on chlorinated municipal water. It is positioned after the sediment stage and before the RO membrane, where it removes residual chlorine and organics that a sediment filter alone cannot intercept. Left untreated, chlorine in feed water will degrade and eventually destroy a thin-film composite (TFC) membrane, making a functional carbon block pre-filter a non-optional part of any RO system on city water.
The 10in industry-standard form factor fits the IceCap Smart RODI system as well as virtually every other brand's standard filter housing. This is a CTO (Chlorine, Taste, Odor) carbon block, which treats for chlorinated municipal water. If your water utility uses chloramine rather than chlorine, this cartridge will not provide adequate protection — see the IceCap Chloramine Reducing Carbon Block instead.
Removes chlorine and organics at the second stage of a standard RO pre-filter sequence
5 micron rating blocks fine particulates that pass through a coarser sediment stage
Fits any standard 10in filter housing, including the IceCap Smart RODI system
CTO formulation treats chlorinated municipal water; not rated for chloramine removal
For use with microbiologically safe and adequately disinfected water only
Flush for a minimum of 10-15 minutes before directing output to the RO membrane
Hobbyists on chlorinated municipal water replacing an expired carbon block in an IceCap or compatible RO system
Reef and freshwater aquarium keepers maintaining the pre-filter stage of a multi-stage RO or RO/DI system
Anyone building a new RO system using standard 10in housings who needs a reliable, straightforward carbon block
Confirm your water utility uses chlorine, not chloramine, before buying this cartridge. CTO carbon blocks treat for chlorine. If your municipality has switched to chloramine, this filter will not adequately protect your membrane. Request a water quality report from your utility to confirm.
Always flush for at least 10-15 minutes before use. Carbon fines are released during the first flush. Do not run the output to your RO membrane or aquarium until the initial flush is complete.
Replace on schedule, not on taste or smell. Chlorine removal capacity declines gradually before it becomes detectable. Replace this cartridge at your system's recommended service interval to prevent membrane damage.
Change the sediment and carbon block together. If the sediment pre-filter is clogged or exhausted, it can push particulates toward the carbon block, reducing the carbon block's effective service life. Replacing both at the same time during routine maintenance is the cleaner practice.
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