Platy bullying

Hey everyone,
I’m hoping for advice as I have no idea what to do. I’ve had 2 platy fish for 2 almost 3 years there both males the bigger male has always bullied the smaller one just usually chasing him a little but for the past week he has gotten out of control to the point my smaller platy stopped eating and constantly hid away even then the bigger platy would search the tank find him and constantly nip him he would be persistent all day long. I’ve had to remover the bigger into the breeder box where he has been since yesterday the smaller is now eating and out of hiding but just sits next to the bigger platy in his box near enough most of the time. They both seem pretty fed up and I feel bad him being in the box. I’m not sure what changed his behaviour he never bothers any other fish and they are all doing fine. Any advice on what I can do to help this situation?
Thank you in advance

How big is the tank and what other fish are in there? Could be an option to add a few more

The tank is 54 litre and I have 6 neon tetras, 6 guppy’s and 3 ghost shrimp. Do you think adding another male platy may help?

ShelbyLeigh said:

The tank is 54 litre and I have 6 neon tetras, 6 guppy’s and 3 ghost shrimp. Do you think adding another male platy may help?

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It's not really a good sized tank for the stocking which you have. You also have a mix of hard and softwater fish. I'll refer you here - www.seriouslyfish.com - for you to find the right combination of fish for the size of your tank and hardness of your water. It should help you going forward

ShelbyLeigh said:

The tank is 54 litre and I have 6 neon tetras, 6 guppy’s and 3 ghost shrimp. Do you think adding another male platy may help?

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Stocking is all about how well you can take care of your fish. You have 8 fish and three shrimp in a 14g tank. That is more than a gallon of water per fish (which is something I used to use). I recommend using AQAdvisor's stocking website, it is AWESOME.

Personally, if I was faced with this issue (which I was), I would remove some fish and restock the tank. Here is how I would do this...

Remove the tetras and the aggressive male (take them back to the store or re-home them to a friend, they might not give you your money back though).
Then, add three female platys (generally speaking, 2:1 is fine for platys but I would be safe and do 3:1 like you would with mollies).

With this grouping of fish, you have hard water fish together. Now, you might have to purchase a larger filter and be on top of your water changes. Platys are not large fish, they do not need a TON of space to move around in. They are also not schooling fish, but rather community fish, meaning you need less of them to stay happy. They can even live on their own!

To help with stocking (besides staying clean and having a good filter), stock your tank with plants! This will help absorb toxins in the water such as CO2 and ammonia, especially moss balls. It will also help with any aggression by putting something in their line of sight at all times.

Good luck!

carligraceee said:

Stocking is all about how well you can take care of your fish. You have 8 fish and three shrimp in a 14g tank. That is more than a gallon of water per fish (which is something I used to use). I recommend using AQAdvisor's stocking website, it is AWESOME.

Personally, if I was faced with this issue (which I was), I would remove some fish and restock the tank. Here is how I would do this...

Remove the tetras and the aggressive male (take them back to the store or re-home them to a friend, they might not give you your money back though).
Then, add three female platys (generally speaking, 2:1 is fine for platys but I would be safe and do 3:1 like you would with mollies).

With this grouping of fish, you have hard water fish together. Now, you might have to purchase a larger filter and be on top of your water changes. Platys are not large fish, they do not need a TON of space to move around in. They are also not schooling fish, but rather community fish, meaning you need less of them to stay happy. They can even live on their own!

To help with stocking (besides staying clean and having a good filter), stock your tank with plants! This will help absorb toxins in the water such as CO2 and ammonia, especially moss balls. It will also help with any aggression by putting something in their line of sight at all times.

Good luck!

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The "gallon per fish" method is massively outdated as its very flawed. You've also suggested 3 female plattys to one male which means within a couple of months that tank will be packed full of fish as they will prolifically breed. Stocking has nothing to do with how well you can look after the fish, its about which fish are suitable to eachother, the water conditions you can provide and the space you're enabling them to have. I could cram a pair of angelfish into a 5G if I wanted to, but I wouldn't because its cruel

EllRog said:

The "gallon per fish" method is massively outdated as its very flawed. You've also suggested 3 female plattys to one male which means within a couple of months that tank will be packed full of fish as they will prolifically breed. Stocking has nothing to do with how well you can look after the fish, its about which fish are suitable to eachother, the water conditions you can provide and the space you're enabling them to have. I could cram a pair of angelfish into a 5G if I wanted to, but I wouldn't because its cruel

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I understand what you are saying. I always recommend having a good ratio of 3:1, if you don't want fish, let them get eaten or take them to your LFS.

I said I USED to refer to that rule- I no longer do that HOWEVER, I mentioned it only because it can give a decent baseline.

And yes, stocking is 80% how well you can keep the water quality healthy. Fish like the ones she has do not need a lot of space, therefore she can put more in a smaller tank. What you brought up is not the same thing. Angelfish NEED a lot of space, platys do not since they can only get to around 2 inches. Guppies are also very small, only reaching 1.5 inches to 2 inches as well. 15g is plenty of space for those fish.

I would not recommend her to stuff 8 fish into a bowl, but her tank is not a bowl. It is plenty of space. I would know because I have livebearers. They get along really well (with the right ratio) and with well-taken care of water conditions, can be kept in smaller tanks (10g, 15g, 20g, etc).

Your angelfish scenario IS cruel- mine is not.

The OP's water also needs to be taken into account. Rehoming the tetras and getting more platies would work if the water is hard. If it's soft, rehoming the platies and getting more soft water fish would be a better option.

Essjay said:

The OP's water also needs to be taken into account. Rehoming the tetras and getting more platies would work if the water is hard. If it's soft, rehoming the platies and getting more soft water fish would be a better option.

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Totally agree! I am biased to livebearers so I recommended her take back the tetras and getting more platys!

carligraceee said:

Totally agree! I am biased to livebearers so I recommended her take back the tetras and getting more platys!

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That little tank will be overrun with fry in no time....as mentioned above.

Slaphppy7 said:

That little tank will be overrun with fry in no time....as mentioned above.

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I know- I explained what the OP could do if they had a problem with that. My livebearers have given birth twice in the last few months... I think it depends on the fish. There are easy solutions to fry.

Since you said they're both fed up, do you have water test results please?

Any other changes or recent additions/removals from the tank recently? Might even be something as simple as revamping the planting. If you cut a lot of plants back or removed some, that removes some hiding places and opens up line of sight, so can increase chasing and bullying.

Also is it possible that the smaller platy is ill, or elderly? Fish will peck at and chase off a fish that is showing signs of weakness, they can be brutal about it. But it's normal, since a sick or weak fish sends signals that attracts predators in the wild, so chasing them away makes perfect sense. In a tank however, the sickly fish has no where else to go.

Personally, I wouldn't add female platies to this size tank. I have a couple of tanks this size. Not bad for guppies, sorta okay for platies, not big enough for mollies. I have livebearers too, platies can get surprisingly big sometimes! I have a blue platy female that is huge, much bigger than any other platy I've had. Must get a pic of her. A male only tank can work with some tips and tricks, and three females would be churning out a LOT of fry, so you'd need another tank to remove the fry to, and someone willing to take the fry since not all fish stores will. You can't rely on the parents to eat all the fry, mine rarely eat many of the young.

AdoraBelle Dearheart said:

Since you said they're both fed up, do you have water test results please?

Any other changes or recent additions/removals from the tank recently? Might even be something as simple as revamping the planting. If you cut a lot of plants back or removed some, that removes some hiding places and opens up line of sight, so can increase chasing and bullying.

Also is it possible that the smaller platy is ill, or elderly? Fish will peck at and chase off a fish that is showing signs of weakness, they can be brutal about it. But it's normal, since a sick or weak fish sends signals that attracts predators in the wild, so chasing them away makes perfect sense. In a tank however, the sickly fish has no where else to go.

Personally, I wouldn't add female platies to this size tank. I have a couple of tanks this size. Not bad for guppies, sorta okay for platies, not big enough for mollies. I have livebearers too, platies can get surprisingly big sometimes! I have a blue platy female that is huge, much bigger than any other platy I've had. Must get a pic of her. A male only tank can work with some tips and tricks, and three females would be churning out a LOT of fry, so you'd need another tank to remove the fry to, and someone willing to take the fry since not all fish stores will. You can't rely on the parents to eat all the fry, mine rarely eat many of the young.

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See I would debate the whole 15g not being big enough for mollies or just big enough for platys. I just don't believe that they produce as much as you guys think. My mollies are in a similar size tank with platys and they are thriving (every stocking calculator, even the AQAdvisor one says I am not overstocked). HOWEVER, I do agree that platys can get pretty big. If you feed them really well (3 times a day+ or just with protein rich food) they can get really large!

carligraceee said:

See I would debate the whole 15g not being big enough for mollies or just big enough for platys. I just don't believe that they produce as much as you guys think. My mollies are in a similar size tank with platys and they are thriving (every stocking calculator, even the AQAdvisor one says I am not overstocked). HOWEVER, I do agree that platys can get pretty big. If you feed them really well (3 times a day+ or just with protein rich food) they can get really large!

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I've bred livebearers, tons of them, big spawns. As said above, for some reason, Platties just aren't really interested in eating their young like guppies do so most of the babies survive in the main tank without any human interference. This means that a tank will become overstocked pretty fast and not everyone is able to move on fish easily when this happens. Especially in areas where people are in lockdown.

carligraceee said:

See I would debate the whole 15g not being big enough for mollies or just big enough for platys. I just don't believe that they produce as much as you guys think. My mollies are in a similar size tank with platys and they are thriving (every stocking calculator, even the AQAdvisor one says I am not overstocked). HOWEVER, I do agree that platys can get pretty big. If you feed them really well (3 times a day+ or just with protein rich food) they can get really large!

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I just had a trio of really huge black mollies, that absolutely would have been cramped if I'd put them in my 15 gallon. I'm not saying that they'd produce more waste than the tank could handle - my 15 gallons have canister filters that could easily handle the waste from mollies- just saying that I don't think they'd have reached that size, nor lived to the eight or so years that my trio did, if they'd been in a 15 gallon. Platies and mollies are stronger swimmers too, and they made use of the space in a larger tank. Personally, I wouldn't go smaller than 20 gallons for mollies, and I'd be careful about platies in 15 gallons and wouldn't go smaller than that for them.

But again, this is personal opinion based on my own experiences, so your milage may vary! I'm not gonna drag someone out into the town square for stoning if they have a molly in a 15 gallon.

Photos of my large black mollies. These three have since passed, but I have a trio of their offspring. They made this 57 gallon tank look small. The yellow mollies were adults here, as were the santa and blue platies, and the brone cory. They got HUGE, just kept growing as they aged, and would absolutely have been cramped and stunted in a 15 gallon.


Compare the black and silver mollies to the adult male guppy behind them. And the adult sant platy just in front of them. The very large blue platy female I have is behind them, and she's grown since these photos...



A+s I said, this tank is 57 gallons, and they used the whole space, making it look easy. Some mollies can get really big if allowed to grow to their full potential, and they're strong swimmers, so I wouldn't confine them to a nano tank.+
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