Neon tetra fish care, size, life span, tank mates, breeding

Hi there, I have recently bought my daughter a small aquarium, to which we introduced a dozen Neon Tetra. In the 3 weeks my daughter has had the aquarium all of the fish have died. The latest culling was today after a water change. 6 fish died within a few hours of each other. The PH level has been fine but I suspect the chlorine level from the tap water is the culprit. Is there a precautionary treatment I should of done prior to adding the tap water? Great site, Craig.

We need to know more about your water parameters. With your aquarium test kit, test your ammonia, nitrite and nitrate levels as well as your tap water for chlorine and chloramine. It is quite possible that chlorine or chloramine is the culprit. There are products on the market that will neutralize chlorine and chloramine.


Try using something like AquaSafe. If your tank was not cycled then another potential culprit is ammonia. Check out the Nitrogen Cycle for more information.

I think a lot of people have the common misconception that just because the neon tetra is so popular that they can just put it in any tank with any water and it will flourish. I have a species tank with 12 neons and 2 leopard cory cats and I have found that black water extract, a wide variety of food, and a ph of around 6.5 to 6.8 and my neons color is great and the health is excellent. Just like any fish they have requirements too.

If you can provide good filtration, a suitable heater and your tank has completely cycled you may be able to have one or two neons in it. Having a smaller tank means that you will have to monitor your water paramenters more diligently because it will be less stable than a larger tank. Using a small tank setup also means that you won’t get to see the beautiful schooling behavior that a group of 6 or more neons would display.

These are fun fish. I had three senior zebra danios that chased each other around the tank. Then the tetras started doing that too! Keep in mind that they are NOT a very hardy fish, though. One got close to the filter tube during the night and got stuck to the side of it. In the morning I found a very dead and very mangled tetra. Also, the heater had a MAJOR malfuntion and the water got way too hot. When we took the heater out of the water, it sizzled. The zebra danios and goldfish acted like nothing was wrong. As for the tetras, they literally baked. Oh, and was also dumped the faulty heater in the garbage and bought a new one. So be careful with tetras(and old heaters)! I had a run of bad luck killing mine.

I’ve found that the Neon tetras I’ve kept had a hard time with hard water (high KH). Southern California tap water is extremly hard. I managed to keep my neons healthy by using softer water. Just make sure it’s not too soft, as it’s hard to manage PH is water that is extremly soft (too few buffers)

I have found them to be hardy once they get past the acclimation process (introducing them into your tank after purchase). There is better chance of success if you float them for more than an hour with every fifteen minutes adding a small amount of water from the tank to the bag. Using Blackwater Extract, some live plants, and making sure to do partial water changes bi-weekly are good ideas.

Also make sure the neons get their food! I used to have neons with zebra danios and the danios were eating all the flake food before it sank to the neons and some died as a result. Don’t give up on neons if you have early failures. They are one of the neatest colored tropical fish available and you can keep them just like easier danios/barbs if you treat them like a fish needing a few ‘special’ precautions.