Neon Tetra Help

[BettaGirl_666]

Hello!

I was feeding my neon tetras this morning when I saw that one of them (the smallest) had gotten a black tinge on the top of it's dorsal fin. It's been nipping at the other tetras frequently today, and the days I've had it before it was rarely doing so. Is this normal with tetras, or is something wrong with it?

 

[Byron]

How many neon tetra do you have together? And we might as well know the tank size, as this could come up in the on-going discussion.

 

[Colin_T]

Any chance of a picture of the fish and aquarium?
If the pictures are too big for the website, set the camera's resolution to its lowest setting and take some more. The lower resolution will make the images smaller and they should fit on this website. Check the pictures on your pc and find a couple that are clear and show the problem, and post them here. Make sure you turn the camera's resolution back up after you have taken the pics otherwise all your pictures will be small.

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Test your water quality for ammonia, nitrite, nitrate and pH. Post the results in numbers here.

How long has the tank been set up for?
How often do you do water changes and how much water do you change?
Do you gravel clean the substrate when you do a water change?

How long have you had the fish for?
What other fish are in the tank?
What are the tank dimensions (length x width x height)?

 

[BettaGirl_666]

I have four neon tetras in that tank with a male betta fish. The tank size is ten gallons. The test results for nirate and ammonia were about 30 for nirate, and 0.25 for ammonia. The tank has been set up for about three weeks to a month now, I think, and I have not done a water change yet, but will probably do so today or tomorrow. I've had the tetras since this Saturday. Will send pictures soon.

 

[Byron]

I have four neon tetras in that tank with a male betta fish. The tank size is ten gallons. The test results for nirate and ammonia were about 30 for nirate, and 0.25 for ammonia. The tank has been set up for about three weeks to a month now, I think, and I have not done a water change yet, but will probably do so today or tomorrow. Will send pictures soon.

A couple other issues (aside from the black spot for which we will need a photo) here.

Nitrate at 30 ppm is high, too high for fish. I assume this is due to the establishment of the cycle, but you need to do some water changes to keep nitrates as low as possible, and always below 20 ppm.

Second issue is the mix of fish. Neon tetras should not be combined with a male Betta. I made this mistake many years ago (40 now) and one evening watched my Betta easily devour a neon tetra. Bettas are not community fish, and forcing them into this situation is not kind to them or the other fish. And before you say it, you may have seen nothing yet, but it is early days (a month or less) and once the fish settle in this can quickly change. Even if you do not see physical interactions, the fish are releasing chemical signals and these are stressful.

 

[Colin_T]

You should be doing water changes every week, or any day there is an ammonia or nitrite reading above 0, or a nitrate reading above 20ppm.

I recommend doing a 75% water change and gravel cleaning the substrate each day until the levels are back to 0. Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

The neons are probably arguing due to low numbers. Neon tetras naturally occur in groups of thousands so keeping 4 in a tank can stress them out. If the Betta is not getting angry at the neons, you could increase their numbers after the filters have established. But you will have to monitor them closely and if the Betta shows any aggression towards the neons, they will have to be separated. All tetras (including neons) should be kept in groups of at least 10 and preferably more.

 

[BettaGirl_666]

I'm doing another nitrate test in case I read it wrong. My pictures are having trouble getting to my email, and I will do a water change when the test is done.

 

[BettaGirl_666]

Here's a picture of the neon tetra with black fins.

 

[Byron]

Here's a picture of the neon tetra with black fins.

I would not worry about that, I have seen it many times myself in various characin species. Here is a photo of a shoal of neons, some have black in the dorsal fin.

 

[BettaGirl_666]

I'm glad it's not an illness! Thank you all for your help!

 

[Byron]

I'm glad it's not an illness! Thank you all for your help!

You do need more neons though as both Colin and I mentioned. With just four you are inevitably going to find them becoming stressed and that means aggressive, and the Betta in there is only going to make this even worse.

 

[BettaGirl_666]

I know. I will get more when possible.

 

[BettaGirl_666]

Quick question: When I add more tetras, will they start their own group, or will they all school together?

 

[Byron]

Quick question: When I add more tetras, will they start their own group, or will they all school together?

They will shoal together. They will likely in time spread out, as this is a very small space, but it is needing a group of them in the tank that is the crucial thing for their well being.

 

[seangee]

Just to elaborate on what @Byron said. They will stick close together when they are stressed or insecure. Once they feel comfortable in their surroundings they will spread out so this is actually a good thing. And having more of their own kind in the tank is one way to make them feel more secure.