# When platy fish go bad (Stocking ideas?)



## Cupkayke (Jul 27, 2016)

So I've been running a very successful platy and tetra tank for months now, up until about a week ago when one of my platys went rogue and decided to try to kill every fish in sight. I've ruled out everything it could be, the tank has equally plenty of room and plenty of plants, and there are no girls to fight over, and he also tries to kill the tetras (but specifically one platy in particular). I've come to the conclusion he just became aggressive and he hasn't calmed down since. I've been keeping him in a 5 gallon by himself at the moment, I've tried putting him back in the community tank but before I can even release him from the net he tries to kill the other fish (I'm talking serious injuries, not nipping, fins being entirely torn off) So I started to think, perhaps he can live on his own, but after being in the 5 gallon for about 3 days he hasn't moved from one spot, not even to eat, and I've decided he's just too lonely. So I'm going to attempt to put him in a tank with slightly bigger fish, and bottom dwellers. So, now to the actual question, what should I put in the tank? I'm starting out with a 10 gallon in case this whole thing fails so I don't waste my money. What fish can I put with a mad platy in a 10 gallon that will convince him to stop eating other fish. And no I will not return him, I actually like the little chomper and want him to be normal again. If anyone has any better ideas let me know. Is there fish anger management?

Also, does anyone have any clues as to what caused his aggression? This is my first time dealing with a problem outside of disease so i'm a bit clueless to the whole thing.


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## RussellTheShihTzu (Mar 19, 2013)

Do you have any female Platys? If not, it's sexual aggression/frustration. It may look as if he's trying to kill them but it could be he's trying to breed.


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## Cupkayke (Jul 27, 2016)

I don't have any females, however I've become quite aware of the difference between them trying to mate with one another and what this platy in particular is doing. I plan on getting females once I upgrade to a larger tank because I'd like to breed, but as of now the platys are taking their frustration out on eachother. This platy is literally tearing off fins, ripping holes in fish, and it seems he goes afyer the tetras too, something my other platys dont do when they're trying to mate. He almost killed one of my other platys, and left one with its mouth ripped off, and left a tetra with no dorsal fin. The guy's just angry from the looks of it.


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## RussellTheShihTzu (Mar 19, 2013)

I didn't "speak" clearly. What I meant was the killing behavior stemmed from the frustration of being unable to breed.


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## Cupkayke (Jul 27, 2016)

My bad for misunderstanding. What should I do in your (or anyone else reading's) opinion? I have the option to get a female to breed but I also am on a college kid budget, of course i'll spend what I have to for my fish because i'm the one that decided to own them, but I've never bred before and to be honest I was told by a breeder it would be fine to keep 4 male platys together without females so I didn't really expect this. He came from a tank of all males so I thought he'd be fine but I guess not.


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## halleyana (May 25, 2016)

The best case scenario with platys is to have the majority female and a few males (usually a 2 to 1 ratio is the minimum recommended). I have 8 female platys and 3 males in one tank and even with all the females one male will become "dominant" and will try to keep the other males away from "his" girls. I also have a female betta in that tank, who breaks up their nonsense when she deems it necessary. It's just a balance of having enough females to go around (because the males WILL harass them to breed) and having enough cover so the less dominant fish can escape the more dominant. It also changes sometimes, which fish is getting "picked on". 

If you do decided to breed, platys are very simple and you just have to have a male+female=babies. They will eat their own fry (as will other predators in your tank) so if you want the fry to survive you need to have a separate tank for them. In my tank, I don't want a million babies, my female betta does a good job of population control along with the other platys and I have about 1-5 babies survive each batch. 

They are a social fish though, you really want to have a minimum of 3 platys together, so if you're okay with babies, I'd get 2 females to put with him in a separate tank, or get enough females for the males in your other tank (if you have room).


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## Falcon (Jan 9, 2008)

With South African cichlid tanks, you want a 1 male 3 female scenario. Otherwise they get super aggressive towards each other.


This is starting to sound similar to what's going on with your platy.


In a case like this, usually one would rearrange the decorations in the tank and it changes the pecking order.




Rearranging the decorations will cut down on the aggressive behavior and one of the other males, hopefully a less aggressive one takes over as dominant male. 


Or you can attempt a few females in a separate tank. If there isn't enough females to go around in the main tank, you will run into more aggression issues. Best to separate what you plan to breed.


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