No plumbing, no landlord permission, moves with you. Of six countertop RO systems, only one is fully certified for its contaminant claims — we verified the paperwork and the 5-year costs for all of them.
Only one under-sink filter here has an end-to-end verified PFOA/PFOS certification. We checked every claim against certifier listings and ran the 5-year filter math — from around $198 to around $2,188.
Well water treatment starts with a lab test, not a product. Five systems matched to iron type, sulfur, and bacteria — with manufacturer ratings, honest limits, and five-year costs.
Five whole-house systems compared on what we could actually verify: certifications, flow rates, and true five-year costs — including the certification gaps most roundups skip.
A three-way head-to-head at ~48,000 grains that starts with the category line most comparisons blur: SpringWell’s FutureSoft FS1 is a TAC conditioner that does not remove hardness, while the SoftPro Elite and Fleck 5600SXT are true ion-exchange softeners. Claims checked against certifier directories, five-year costs with salt and media counted, and a verdict by water problem.
Five salt-based softeners ranked the TapChecked way: certification listings we could actually find, delivered capacity at an efficient salt dose (not the box number), valve serviceability, and full five-year costs including salt. Fleck 5600SXT tops the list; two popular internet brands carry certification claims we could not verify.
AquaTru Classic vs Waterdrop K19-H vs Frizzlife WB99-C: verified IAPMO certifications, footprint, remineralization — and a full 5-year cost table with the arithmetic shown.
Five under-sink RO systems checked against the actual NSF, WQA and IAPMO listings — three are certified for TDS only — with full 5-year filter costs and an honest top pick.
NSF/ANSI 177 certifies free chlorine reduction only — not chloramine, lead, or softening. Certified Sprite and Culligan picks, honest Aquasana and Jolie distinctions, and five-year costs.
Ion exchange removes hardness to near zero. TAC and chelation only inhibit scale and still test hard. Mechanisms, the NSF 44 gap, and five-year costs compared.