The answer to this incredibly popular question is yes, all tetras, including neon tetras, definitely need a water filter to ensure that their water is aerated and allows for beneficial bacteria growth. Tetras originate from South America, and spread across the entire continent, with the highest concentration found in the Amazon River Basin. These water environments are hard to replicate in captivity, which is why a filter is most certainly needed.
However, you can set up a neon tetra tank without a filter, provided you are experienced and understand the significance of a heavily planted tank and deep substrate when it comes to neon tetra requirements.
Can Neon Tetras Live Without A Filter?
They can live without an aquarium filter, but it is not recommended unless you have experience with tetras or other tropical freshwater fish. Filters are brilliant for the growth of beneficial bacteria and also help aerate the water by creating surface agitation making for ideal neon tetra water conditions.
To ensure your neon tetras have the best chance of surviving without a filter you must make sure that you have populated your tank with enough live plants to remove toxins from your fish's bioload in the water and provide some oxygen.
Another useful tool when trying to create a water current in your aquarium is a bubbler. Bubblers do a great job at removing dead water spots and creating consistency within your tank whilst also producing oxygen within the water.
Neon Tetra Water Conditions in the Wild
In the wild and in their natural habitat, neon tetras are found residing in blackwater or clearwater streams in the Amazon River Basin. The water temperature ranges between 68-82°F (20-27.75°C). These waters typically have a slow-moving current running through them as well as some still, shallow pools.
Do Neon Tetras Require a Current and Moving Water?
Neon tetras certainly require a slight current to create slow-moving water, as it best replicates their natural environment in the Amazon River Basin. Fortunately, it is rather easy to replicate this in your fish tank, using a standard filter or internal filter. Even wavemakers and pumps will do a good job if your aquarium is big enough.
How Long Can Neon Tetras Live Without a Filter?
Based on experience with neon tetras and knowing their requirements when it comes to needing a filter or some form of light current in their aquarium; with no current in their tank creating some form of water flow, and no filter in their tank to help regulate their water quality, Tetras would likely only last about 12 hours before you start noticing some negative effects. Pregnant neon tetras will have much less of a tolerance to still, non-filtered water, which is something to keep in mind.
Conclusion
Water filters are pretty useful for most fish you will likely house during your time as a hobbyist. Sure, there are some fish that require a filter more than others do, and the neon tetra is certainly one of those. Not only should you acquire one to create a slow-moving aqua environment current that mimics their natural habitat, but by having one you will also save some time with ongoing maintenance as your tank will require fewer water changes due to having cleaner water.
