# Evil Neon Tetra



## Cryztyle (Feb 28, 2014)

I cycled my 5 gallon tank and put in some live plants and then I introduced 5 neon tetras.... apparently one of the tetras is evil because it chased all the other tetras around relentlessly. I chalked it up to new tank anxiety and decided to turn the lights off in the tank and allow them to get used to the new place but when I woke up this morning all the fish except the evil one was dead  I've never had this experience before with tetras I'm honestly so shocked.


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## ThatFishThough (Jan 15, 2016)

A 5 gallon is FAR too small for the neons. They need at least 20G and should be in groups of 6 or more. The "evil" one probably was being territorial because the tank was too small.


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## Cryztyle (Feb 28, 2014)

Oh No! Now I feel really bad! I didn't realize they needed that much space I just assumed that since they were so small and since I had done it before it would be okay


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## moodynarwhal (Mar 24, 2016)

Everybody makes mistakes. The best way to avoid mistakes is to do research. Hours and hours of research. This forum is a great place to ask questions, and remember, the pet store's info is often incorrect, even if they are well-meaning.


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## RussellTheShihTzu (Mar 19, 2013)

Neons are not territorial; they are shoaling fish and as such need others for safety concerns. They can be aggressive. There can always be one that chases the others in the shoal but that's to show dominance and never results in deliberate injury or death. Neons, however, are very sensitive and unless a tank is fully mature and parameters stable they can die from the stress of a new environment. This is most likely the cause of their deaths and that the one Neon was aggressive just coincidental.

A small shoal of under eight Neons will do well in a 20x10x12; a larger shoal needs a 30x12x12. Long tanks are more shoal-friendly than their tall versions. That's why species sites will give tank footprints and not gallons.

Even with a Betta if you have proper filtration and heaving plantings a five gallon (16x8x10) can have six or eight of the smaller Nano fish under 1". Or three Dario Dario if you're willing to feed live and frozen foods.


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## ThatFishThough (Jan 15, 2016)

I didn't mean my post in a negative way. As moodynarwhal said, everyone makes mistakes.

Russell, I have to disagree that they are territorial. I had a small shoal of Neons in my 20 for a while, and each fish had a "territory" inside of the area where the fish swam together. Occasionally one would chase the other out of the territory. Then they would go back to schooling in that area. I would say that they won't _kill_ each other, but will chase each other out of territories.


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## RussellTheShihTzu (Mar 19, 2013)

"Territorial" is when one fish, like the little Dario, defends its section of a tank and will not allow any others to encroach without challenge. These fish are not shoaling varieties and are usually male and will allow only females access.

So Tetra are not "territorial." If they were they would not be able to shoal and they would not allow the ejected member to return. What we see when one momentarily runs another out of the shoal is, for lack of a better word, a spat and at some point most every member of any shoal will do this.

The OP said one particular Neon would chase the other Neons "around relentlessly"; this is aggression. When defending territory a fish does not chase all over the tank; once the others leave its territory the fish stops.


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## KendraPM (Feb 13, 2018)

RussellTheShihTzu said:


> Even with a Betta if you have proper filtration and heaving plantings a five gallon (16x8x10) can have six or eight of the smaller Nano fish under 1". Or three Dario Dario if you're willing to feed live and frozen foods.


I'm really happy to hear that (read that?). I'm not anywhere near comfortable enough with my tank keeping to go try and add anything more than a single fish to a five gallon at this time, the idea that some day I _could _if I was so inclined and was confident in my tank keeping skills makes me feel better. It actually decreases my stress as I was thinking that there was certain fish I was going to have give up the dream of ever owning simply because there were others I'd rather have that I knew would take up all my "fishy room" if you will.


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