Black neon tetra sudden behavior change

[ptk207]

Hi all,

I just found this forum in hopes of finding some help/answers, and I'm reaching out here since this seems like a very helpful community of experienced hobbyists. I'm hoping to get some help diagnosing my black neon's issue.

I do not have the tools/equipment for exact numbers for water parameters, but use test strips to get a good estimate of water conditions (I know, please don't hate me lol). My reading today didn't show any unusual changes or spikes.

It's a 20 gallon high with 1 angelfish, 6 black neons, 6 red serpaes, and 3 albino corydoras. There is a bubble wand/strip for added aeration, mounted filter, and a heater keeping the temp at 78 degrees Fahrenheit, no live plants. I do 25-30% water changes with a vacuum siphon each week. I just did my usual water change yesterday which included a change the filter cartridge to a new one (the the first change since the tank was set up), scrubbed some algae off of the plant decor, scrubbed the tank walls, put decor back in, and topped off the tank with treated water as usual.

Later that night, I noticed one of the black neons constantly hanging under the filter current at a diagonal position, quickly opening and closing its mouth as if "gasping" but it never moves above the surface for a "sip" of air, it just hangs there. Also, I just now noticed that its scales appear raised. All of the other fish are behaving normally and are eating just fine. It's still behaving like that today. I'm wondering if it's either stressed after the water change with the moving of ornaments or something else? I've attached a photo and a short video clip. I appreciate any help! Thanks.

Video:

https://imgur.com/a/YKFvcW2

 

[JuiceBox52]

What are the readings you got from the strips? Was the tank cycled? Did you quarantine your fish? Is he eating?

Sorry for the questions but it helps us figure out what's wrong

 

[ptk207]

Yes, the tank was cycled. Unfortunately, I have no means of quarantining him. He didn't come to eat at feeding time this morning. I attempted to entice him with food just now and he did try to come near where I was dropping the flakes but the other neons got to them first, so he retreated back to his corner. All of my neons are usually pretty dominant when it comes to feeding time, even the angelfish gets intimidated. He does appear bloated too which is probably contributing to the raised scales, so I'm wondering if maybe it's constipation? My neons do tend to eat viciously ironically.

I just did another test strip reading so here's a pic of the results read at 60 seconds:


These readings have been the same this way for a few months since I cycled the tank and established the community, with the fish remaining calm and stable.

 

[Byron]

I would suggest this fish has a disease. I have very little experience with diseases, so I will not guess, as treating for "x" can be worse than nothing if you don't know the actual issue. Members like @Deanasue or @Colin_T have better guidance than I can give here. You need to have a fairly good idea of the actual issue before any treatment should be undertaken.

 

[FishGuest5123]

Hi! If you cleaned the filter and tossed the old one plus scrubbed all of your decor, you probably lost your cycle. Never change your filter until it is falling apart. Simply swish it in some tank water to clean it. Scrubbing the decor does the same thing. It scrubs the beneficial bacteria off. I would do a 50% water change again and be sure to use dechlorinator or water conditioner. Do this daily and watch your numbers. I suggest getting an API Master Freshwater rest kit. Very Easy to use. Those sticks aren’t accurate. If you have an air stone, put it in with the fish for extra oxygen.

 

[ptk207]

Hi! If you cleaned the filter and tossed the old one plus scrubbed all of your decor, you probably lost your cycle. Never change your filter until it is falling apart. Simply swish it in some tank water to clean it. Scrubbing the decor does the same thing. It scrubs the beneficial bacteria off. I would do a 50% water change again and be sure to use dechlorinator or water conditioner. Do this daily and watch your numbers. I suggest getting an API Master Freshwater rest kit. Very Easy to use. Those sticks aren’t accurate. If you have an air stone, put it in with the fish for extra oxygen.

Thanks for your response. I did worry about messing up the bacterial ecosystem, but I decided to clean the plant ornaments since they developed a bloom of algae growth. I use an Aquatech filter that has the bio grid that I leave alone and the carbon filter cartridges. I didn't clean out the filter itself but just tossed the old cartridge since it was so grimey with sludge and fish waste after 2 months. What's your advice about these types of cartridges with activated carbon in them? So far I've seen advice that if it gets to the point where one would have to change the cartridge, they could cut a piece of the old floss padding and add it in with the new cartridge. What are your thoughts on that?

Also, I have a bottle of Fritz Turbo Start in the fridge from when I first moved. Should I add a little of that to the tank water for the current situation? The treatment I already normally use during water changes is API Stress Coat, Stress Zyme, and Quick Start. And I already do have a long air stone in the tank for added oxygen.

I've been watching the black neon and he just chooses to swim against the current of the filtered water flow.

 

[JuiceBox52]

Stress coat and stress zyme are unnecessary and there is evidence that suggests it is harmful to fish over time.

Many of us just use sponge media in our filters. The advice is the same. Rinse it in cold tank water to dislodge the gunk but the bacteria stays

 

[Colin_T]

it's dying from internal organ failure, euthanise it now, then do a 75% water change and gravel clean the substrate every day for a week. Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

 

[JuiceBox52]

That's interesting. How do you tell if its internal organ failure?

 

[Colin_T]

gasping at the surface or near a filter outlet.
sudden bloating and pine coning. (pretty sure that was mentioned somewhere.

 

[Lajos_Detari]

Usually fish at this stage is hard to save as Colin mentioned.

But if you still want to try, you can keep it in a pail with an airstone.
Put Methylene Blue and 2 tablespoons of salt for 20 liter of water into the pail. Reduce dosage for smaller pail.
Add Methylene blue until the water is light blue where you can still see the fish.
Methylene Blue can help to increase oxygen in the blood and help with ammonia and nitrite poisoning.
The salt might be useful if there are gill flukes and bacteria infection in the gills that caused the fish to breathe fast.

If you don't have Methylene Blue, just use the salt.

This will be my last resort for saving a fish. (but no guarantee)

 

[LostBear]

Yes, the tank was cycled. Unfortunately, I have no means of quarantining him. He didn't come to eat at feeding time this morning. I attempted to entice him with food just now and he did try to come near where I was dropping the flakes but the other neons got to them first, so he retreated back to his corner. All of my neons are usually pretty dominant when it comes to feeding time, even the angelfish gets intimidated. He does appear bloated too which is probably contributing to the raised scales, so I'm wondering if maybe it's constipation? My neons do tend to eat viciously ironically.

I just did another test strip reading so here's a pic of the results read at 60 seconds:
View attachment 104908

These readings have been the same this way for a few months since I cycled the tank and established the community, with the fish remaining calm and stable.

Could you quarantine him within the tank itself? Perhaps float a largish jar (with a decent surface area) containing tank water in your aquarium and put him in that? I don't know if this would work, but I'm just trying to think of a way to protect your other fish, and enable him to get something to eat he wants, poor little thing.

 

[Essjay]

The danger with this is that if using methylene blue, some could accidentally get into the main tank - splashing, tub overturn etc. Methylene blue kills filter bacteria which is why you don't want it in the main tank.
It can be used when a fish is just separated for observation, or to separate it from other fish which are picking on it though.

 

[Lajos_Detari]

The danger with this is that if using methylene blue, some could accidentally get into the main tank - splashing, tub overturn etc. Methylene blue kills filter bacteria which is why you don't want it in the main tank.
It can be used when a fish is just separated for observation, or to separate it from other fish which are picking on it though.

Yes, I understand your concern.

I suggested to him to put the fish in a pail with an airstone and not in the main tank. (see my post).
Also, by separating the fish, you can prevent the sick fish from spreading any disease to other fish.

A pail can be easily washed off, though the stain will take a while to be removed.
You can also put boiling water to clean the pail after everything is over.

 

[Essjay]

I agree. Any sort of container outside the tank.