Nitrates
An agricultural runoff problem, and largely outside what a carbon jug does.
Most filter jugs cannot do thisNitrates enter groundwater from fertiliser and livestock, which makes this a rural and agricultural-catchment concern rather than an urban one. Activated carbon does not remove them. Ion exchange can, if the resin is selective for it, which is why ZeroWater is the jug that shows up in nitrate discussions and the ordinary carbon cartridges do not.
How you know you have it
- A private well in arable farming country
- A supplier's water quality report showing nitrate levels approaching the regulatory limit
What works
ZeroWater's ion exchange stage, and Clearly Filtered, which publishes a nitrate figure.
What does not
Carbon cartridges of every kind.
Cartridges that reduce nitrates
Ordered by strength of evidence, not by brand. An independently certified claim outranks a lab-tested one, which outranks a manufacturer’s word for it.
Cartridges that do not
These make no claim here, and that is not a criticism — it is what their manufacturers say. Buying one of these for this problem is the mistake.
Questions
Does a filter jug remove nitrates?
Very few do. ZeroWater's ion exchange stage, and Clearly Filtered, which publishes a nitrate figure.
What does not work: Carbon cartridges of every kind.