I live in Iowa. Which water filter should I buy?
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Illustration: Maura Losch/Axios
Welcome to our new series, Water Cooler Talk, where we answer your water quality and food questions.
- We got several questions last week about buying a reverse osmosis (RO) water filtration system, so let's dive in.
Context: Central Iowa Water Works implemented a lawn watering ban last week because its filtration system is at its limit treating high nitrate levels in the Des Moines and Raccoon rivers, combined with our high summer water usage.
- Our drinking water's nitrate levels are still under the EPA's maximum standard of 10 mg/L. While the EPA standard is 10 mg/L, some studies have linked nitrate levels below that threshold to potential health risks, particularly for pregnant people and infants
- RO systems are the most practical way of removing nitrates in your drinking water (a typical Brita won't cut it).
- Nitrates occur naturally in soil and water, but elevated levels in drinking water are often linked to fertilizer runoff, wastewater and animal manure.
How it works: Think of your RO system like a strict bouncer at the club.
- The door (the filtration membrane) is so tiny that water can squeeze through, while contaminants are left behind.
- Because water doesn't naturally want to move through such a tiny door, the system uses pressure to push it through.
- Contaminants that you don't want are too big to get past the bouncer, like nitrates, lead and arsenic.
State of play: The biggest decision is whether you want to lose counter space or cabinet space under your sink.
- The other thing to look for is whether the filtration system meets NSF/ANSI Standard 58 for RO systems, per Wirecutter.
- Wirecutter recommends Cloud RO ($600) for under the sink because it's quiet and compact. They also recommended AquaTrue Classic (starting at $420) for a countertop model.
Linh's thought bubble: I use a cheaper countertop RO system that wasn't recommended by Wirecutter, and isn't certified.
- But when I tested my nitrate levels before and after using test strips, there was a noticeable decrease.
The big picture: Another thing to consider is whether you want to add minerals back into your water, which can influence which system you buy.
- But be wary of people out there taking advantage of Iowans' current water concerns and jacking up prices.
The bottom line: You can test your drinking water by requesting free nitrate test strips from the Izaak Walton League.