Fighting Neon Tetras

Hello,

We have a 30 gallon with 3 Orange tetras, 2 panda Corey's, and 6 neon tetras. We recently added 3 of the neon tetras and they were initially schooling and seemed fine until a few days later. I tried to separate the culprit until I noticed that once it was separated that the others were still having issues. It seems that they are pretty much all doing it, its not just one or two culprits. A few have torn fins now, so we are for sure starting to worry about how to deal with them long term.
The orange ones, which are the bigger of the tetras, are totally fine by the way, they aren't nipping or anthing.

Do we need to add more tetras?

We can't afford to set up another tank, we just had to remove our shrimp because our panda Corey's, or so we presume, we killing them.

What other possible options do we have?

 

The fish that you have are all schooling or shoaling fish. They really should be in the largest groups possible and for tetras that can mean a reduction in aggression among themselves and towards other tankmates.

How long has the tank been set up? Did you cycle it before you got the fish? What are your current parameters?

Welcome to the forum!

 

I'd add more tetras to lessen aggression.

 

When you add new fish to an existing school a new pecking order will have to be established. This is natural behaviour.
Leave "the culprit" in and provide some extra places to hide (plants).

 

The fish that you have are all schooling or shoaling fish. They really should be in the largest groups possible and for tetras that can mean a reduction in aggression among themselves and towards other tankmates.

How long has the tank been set up? Did you cycle it before you got the fish? What are your current parameters?

Welcome to the forum!

We've had the tank for nearly 3 months, it's cycled and stable (it took us a bit to get to that point, but we're there). The ph is at about 7. What other parameters are there I should be listing? I'm still pretty new to fish forums.

 

Ammonia, nitrites and nitrates

 

I agree with the great advice above. I keep my Neon Tetras in a shoal of twenty and aggression is dissipated. From time to time males will fight over spawning territory prior to inviting females to mate.

Also check the temperature is 74F as I noticed significantly more fighting at 78F.

 

W

When you add new fish to an existing school a new pecking order will have to be established. This is natural behaviour.
Leave "the culprit" in and provide some extra places to hide (plants).

We have a fairly large center piece with a few hiding places with many

Ammonia, nitrites and nitrates

Nitrates and nitrites are fine, one of those two is in the tank, but at a very low level. I'm not sure about the ammonia in the tank. I'm going to take water to be tested at petsmart and then go buy a few more tetras at our local pet store because the last 3 neons we got were from petsmart are the ones we think are causing the aggression.

 

Your tank is very empty, not giving the tetras hiding places they prefer, which is some kind of tall plant they can zip behind. Your tetras, not your cories, were likely eating your shrimp as they are known to do that, cories will eat dead ones but they will not go out of their way to kill and eat live ones.

 

W

We have a fairly large center piece with a few hiding places with many

Nitrates and nitrites are fine, one of those two is in the tank, but at a very low level. I'm not sure about the ammonia in the tank. I'm going to take water to be tested at petsmart and then go buy a few more tetras at our local pet store because the last 3 neons we got were from petsmart are the ones we think are causing the aggression.

Do you know about the nitrogen cycle? Chances are that your LPS doesn't so when they test your water write down the exact results and don't take their word that everything is fine or not. If you didn't add an ammonia source to your tank in the weeks prior to buying fish then it's likely that your tank is not cycled.

 

W

We have a fairly large center piece with a few hiding places with many

Nitrates and nitrites are fine, one of those two is in the tank, but at a very low level. I'm not sure about the ammonia in the tank. I'm going to take water to be tested at petsmart and then go buy a few more tetras at our local pet store because the last 3 neons we got were from petsmart are the ones we think are causing the aggression.

Sorry to say but in the tankpic I don't see a lot of hidingplaces like I mean / fish need.

 

Your tank is very empty, not giving the tetras hiding places they prefer, which is some kind of tall plant they can zip behind. Your tetras, not your cories, were likely eating your shrimp as they are known to do that, cories will eat dead ones but they will not go out of their way to kill and eat live ones.

Our shrimp were all fine, two that went missing were brand new and we've had the other shrimp for about a month to two months prior. The third they ate was the only evidence we had that any had been eaten and it was one of our oldest and they looked super healthy that day. We've only had one actually die but I'm pretty sure it was either old or got stressed out when we moved all the shrimp to their own tank.
The tetras or Corey's had never bothered any of the shrimp prior to us adding about 5 more, so they went nearly two months without bothering them, so not sure why any of them went after the shrimp.

Do you know about the nitrogen cycle? Chances are that your LPS doesn't so when they test your water write down the exact results and don't take their word that everything is fine or not. If you didn't add an ammonia source to your tank in the weeks prior to buying fish then it's likely that your tank is not cycled.

It's cycled. We left the tank alone, other than occasionally testing the water, for a solid month with drive us both mad with the amount of algae growth. But since we left it alone, we no longer have a green algae problem, which we had and was REALLY bad. We now have a brown algae problem. We have a lot of water treatments and additives so we should be okay. We did find that our ammonia was a little high, but we already had the bottle of additive at home to fix that. We do own two different water tests, ones a multipurpose strip and the other is a test tube ph checked. We do also get our water checked at our LPS when we need extra help.

We bought 2 more orange tetras and 4 more neon tetras. That seems to have helped with most of the fighting. We also reorganized the tank to try break any old territories up, per our LPS recommendation.

 

Did you not add an ammonia source for that entire month? If not then your tank did not cycle.

What the nitrogen cycle actually involves is growing bacteria in your filter media that eat your fish's wastes and convert it into less harmful substances until you can remove them through water changes. In a cycled tank your readings should be 0 ammonia, 0 nitrItes, and some amount of nitrAtes because nitrAtes are the end product of the nitrogen cycle.

What are your current parameters?