We do one thing. We do it well.

Where they trip

• It’s expensive — and the bill keeps growing. Premium RO systems run $1,800–$2,500 installed, and that’s only the entry price. The single most-cited customer complaint, across BBB, Consumer Affairs, and Google reviews: filter-replacement and service costs that double or triple year over year. One documented case — a $480 filter kit plus $172 labor, $706 total, on an RO system the customer bought for $2,600 a year earlier. Another customer’s monthly rental rate went from $32 to $34 without notification.
• Owned by private equity. Four PE owners in twenty-two years. Currently BDT & MSD Partners, following a 2021 buyout valuing the company at $6 billion. Before that, Advent International. Before that, Centerbridge. Before that, Clayton, Dubilier & Rice. Every handoff brings the same pattern: margin pressure on the dealers, then on the customers. PE firms exit in 5–7 years, and the metrics they optimize for between now and exit are recurring revenue and rental conversion — not filter prices going down.
• You can’t see a price online or by phone. Their model literally cannot work otherwise — quotes vary 20–40% across franchises. You’re booking a 30-minute in-home appointment before you know what anything costs.
• The in-home demo is a sales tool, not a test. The “blackish-green” precipitator that turns your tap water dark in seconds is an electrochemical reaction that precipitates the normal calcium and magnesium in any non-distilled water. It isn’t contamination. The supplier markets the device explicitly as “an effective sales tool.”
• Quality depends entirely on your local franchisee. Culligan St. Louis is one local owner with one local reputation. A great Culligan experience in Chicago tells you nothing about what’ll happen at your address.

Where they trip

• The great majority of home filters don’t actually filter out the stuff you care about. A Brita pitcher addresses chlorine and taste; it doesn’t measurably reduce lead, PFAS, or disinfection byproducts. A typical $89 countertop filter is the same story. Cheap RO units often skip the catalytic activated carbon stage — the one that handles chloramine, the disinfectant St. Louis-area utilities actually use. That detail isn’t on the box.
• What “good enough” looks like is high. The right setup is a 5-stage RO with NSF/ANSI 58 certification on the membrane (proves lead and arsenic reduction), NSF/ANSI 401 on the carbon stages (proves PFAS, pharmaceutical residue, microplastic reduction), and a catalytic carbon prefilter rated specifically for chloramine. A handful of home units meet all three. Most don’t. We’ve focused on the highest-quality filtration that’s genuinely economical at residential scale — going further means industrial-grade equipment that starts at ten thousand dollars.
• The install is harder than the box implies. Drilling a half-inch hole in granite for the dedicated faucet, mounting the drain saddle so it doesn’t seep, sanitizing the tank before first use, balancing pressure if you tie in a refrigerator line. The plumber section above is mostly about how easy it is to get one of these slightly wrong.
• Warranty covers the box, not the work. If the install is the failure mode, the box warranty doesn’t help.
• Filter inventory becomes your job. Five filters, three change-out cadences, all on you to remember, source, and swap correctly.