Why does my ZeroWater-filtered water smell like fish

There could be a few reasons why your ZeroWater-filtered water smells like fish. It’s possible that the fishy smell is coming from the source water that you are using to fill the filter, in which case you may want to try using water from a different source.
It’s also possible that the filter itself is contaminated with bacteria, in which case you should replace it.
Finally, it’s possible that the fishy smell is coming from something else entirely, in which case you may want to try running the water through the filter again to see if the smell persists. If it does, you may want to contact ZeroWater customer service for further assistance.
Many of the people who have used the ZeroWater water filter claim that the water starts emitting a fishy odor after a certain period of time, especially after a few months of use. I decided to do a lot of research to find out what the chemical was that was giving the fishy smell. Turns out it is Triethylamine that is the culprit.
During the filtration process, triethylamine is produced as a by-product of the filtering process, and it causes the fishy smell. This is attributed to cationic and anionic resins in the ZeroWater that releases trimethylamine.
Trimethylamine is an organic gaseous compound that appears as colorless gas and gives off a fishy, moldy, or ammonia-like odor, although it’s essentially harmless.
They can leach out of the resin, although very slowly. This device is a poor design because the ion exchange bed sits in the purified water, so the TMA slowly but continuously leaches out of the resin into the water.
The amount of trimethylamine released is affected by certain minerals and pH levels of the water source (not microorganisms like bacteria, fungi, mold, or viruses), which would explain why some people notice it and others don’t.
High pH increases the degradation of the resins and, therefore, increases their odor. The fishlike odor at low concentrations changes to odor at higher concentrations.
Since the TMA leaches very slowly (it’s immobilized by the polymer matrix of the ion exchange beads), you would not have any significant amount present in the water, as long as you dispense the water quickly.

This is common RO systems with alkaline filters too, if the acidic RO is not neutralized before contacting the media. The smell is distinctly fishy and becomes worse over time, resulting in undrinkable water.
A better design would be to have the resin suspended above the purified water. You could also overcome this issue by immediately dispensing the purified water into a separate pitcher for storage.
I’m pretty sure that fish/citric taste is related to the temperature the water/filter is exposed to (bacteria or chemical reaction of water touching the filter).
I get the fishy smell when it is past time to replace the filter.
Reading was at 020 this morning, past their recommendation of 009.
I think I’m just going to change out the filter and then pour it into another container as someone else suggested.
Some filtration is better than no filtration
Although we change our filter after testing shows close to or at 6, and wash the entire unit every time we change the filter
clean and disinfect the tank part. the filter cleans the water but if you already have algae, mold, or whatever is making it smell like fish water in your holding tank. Clean out that part.
Besides cleaning the pitcher, I found that the water will taste better for a longer period of time if you empty the pitcher every night & leave the lid off so everything is allowed to dry. Leaving water sitting in the pitcher with the cover on prevents it from drying the standing water will go bad.
The water tasted putrid.
To avoid the smell of fish in the filter, buy 3-4 large silver plates and put them in a jug of water. Silver disinfects water.
This is water, after all – if you leave it to stand and use the same filter all the time, it’s going to get brackish.

I think it’s a great product and customers need to be more informed in their shopping habits, rather than blaming the company.
My TDS reading is 000.. but I get fishy smell if I heat up the water.
Use sterilized(boiled and cooled) water? and keep lid closed. Clean between filter changes.

marcus reynolds