| Device | Primary Use | Limitations |
| Carbon Filter | Removes chlorine, some organic chemicals, resin, general taste and odor problems. | Does not remove nitrate, bacteria, or metals. Periodic replacement of activated charcoal required. |
| Mechanical Filter | Removes sand, soil, and other causes of turbidity. | Requires regular cartridge replacement or backwashing (depending on type) to maintain effectiveness. |
| Water Softener | Replaces water hardness minerals (calcium, magnesium) with sodium Improves cleaning action of soaps, detergent. Prevents scale deposits in pipes, equipment. | Removes calcium and magnesium, replacing with sodium (consult physician if sodium in diet is a health concern). Softened water can be more corrosive than unsoftened water. Periodic backwashing and regeneration required. |
| Iron Filter | Removes iron and manganese that can cause staining of clothes and plumbing fixtures Prevents odor caused by iron, manganese. | Periodic backwashing, addition of potassium permanganate required (frequency dependent on water usage, iron content). |
| Neutralizer | Treats corrosive or acidic water. | May increase sodium or water hardness. |
| Distillation Units | Removes most impurities including minerals and organic chemicals from drinking water. | Distillation takes time and can be expensive. Storage space is needed for treated water. Distilled water has a flat or bland taste. Hard water increases maintenance of distiller. |
| Reverse Osmosis | Removes most dissolved and suspended impurities from water. | Reverse osmosis wastes up to 50% of water. Process requires time and storage of treated water. Hard water clogs membrane. Carbon and mechanical filters may be required to pretreat water. |