Well water filters split into two formats: cartridge housings you service by hand and backwashing tanks that clean themselves, with the media inside deciding what gets removed. Cartridges suit light sediment and taste polishing; tanks carry the heavy work of iron, sulfur and manganese. Picking the format before the media is how people end up with the wrong filter, so start with what your test found.
Cartridge housings: simple, cheap, hands-on
A cartridge housing is a bowl on the line holding a replaceable element: string-wound or pleated for sediment, carbon block for taste and odor. The appeal is low cost and no drain or power requirement. The limit is capacity: on a well with real iron or heavy silt, cartridges load up in weeks and become a pressure restriction, and the ongoing replacement cost quietly overtakes what a self-cleaning tank would have cost. They are the right choice for polishing, not for the main removal work.
Backwashing tanks: the workhorses for iron and sulfur
A backwashing tank holds a deep bed of media and a control valve that periodically reverses flow, flushing captured material to a drain and resettling the bed. Air-injection iron filters add an oxidizing step in the tank head that converts dissolved iron and hydrogen sulfide into filterable particles. Penn State Extension notes iron and manganese carry secondary, aesthetic standards with recommended maximums of 0.3 mg/L for iron and 0.05 mg/L for manganese; wells above those levels are the natural territory of these tanks, and SpringWell's whole-house iron filter is a representative example of the format.
Matching media to the finding
Read the lab report and pick media accordingly: sediment media or a fine screen for grit and silt, oxidizing media for iron, sulfur and manganese, catalytic carbon for odor and taste, neutralizing media for acidic water that corrodes plumbing. Most iron wells run a short sequence, sediment ahead of the iron tank ahead of carbon. If iron is your headline problem, our best iron filters for well water ranking compares the tanks head to head so you can shop from the report rather than the brochure.
Questions people ask about well water filters
Do backwashing filters waste a lot of water?
They send water to the drain during each backwash cycle, which is the cost of self-cleaning. Modern control valves regenerate on measured demand rather than on a fixed clock, which keeps the drain water proportional to actual use.
Can I put a cartridge filter on an iron well to save money?
You can, and you will replace it constantly. Dissolved iron passes through most cartridges anyway, then oxidizes and stains downstream. Real iron levels call for an oxidizing media tank; the cartridge belongs in front of it as cheap sediment protection.
How long does the media in a backwashing tank last?
Years, not months: the bed cleans itself each backwash cycle and is replaced only when its capacity finally fades. The service interval depends on the media type and the water, and the manufacturer states the expected life for each system.