10 Gallon Tank Listing Cardinal tetra, all other fish totally fine

My cardinal tetra has been listing for 8 days. He’ll get a little better but then get worse again. I’ll go over some details and then list all the weather parameters…

On Aug 23, I moved him from my classroom tank to one at home (from hyper platy roommates to 8 ember tetras). All went well and he seemed better: moved more confidently around the tank, actively eating, and no aggression from anyone. Water parameters of the two tanks are very similar to the same.

Aug 30, he started listing about 15degrees to the right. Still active, ate food like normal, all else normal actually. No sinking to tank bottom, no going to surface to gulp air, no trouble swimming. New plants arrived and I put them in the tank as is: Anubias golden, Java fern, and Java moss on steel mesh. Took out latest fake plant; leaving in medium one and 5 small ones. Water parameters since 8/23 had been 0, 0, 0-10.

After researching and seeing it could be an issue with his swim bladder, I fasted the tank for 24hrs (evening of 10/1 to and evening of 10/2) and he looked normal again! And I resumed feeding but gave mostly baby brine shrimp with occasional ground veggies pellets. Trying to give him fiber.

Oct 3, water test was nh3 0.25-.5, no2 0, no3 above zero but below 5. Hadn’t had ammonia above 0 in weeks. Did 40% water change, vacuumed waste out of thin gravel on bottom, and added doses of Prime and Stability. Continued feeding small amounts of baby brine shrimp.

Oct 5, water at 0.25, 0, 0. Did 25% water change, vacuumed again, added small dose of Prime and of Stability thinking the tank was missing bacteria from the large fake plant I removed. Fed baby brine shrimp.

Oct 6, water parameters 0, 0, 0. Cardinal listing almost onto his side in the evening Fasted the tank thru today with him slowly getting closer to upright.

Last night, added a newly arrived Anubias nana petite and Anubias gold coin.

Now he is listing only 10 degrees but once in a while upright. Boiled and mashed up a couple peeled peas and fed it. All fish excitedly checked it out but don’t seem to have liked it. They ate a little. I’ll check for waste sitting around after I post this. Current water parameters are:
NH3 = 0.25 so I added half do
NO2 = 0
NO2 = 0
High pH = 8.2 (normally 7.8)
pH = bluer than 7.6 on api master kit chart (usually about 7.5 by color)
KH = 5dKH (was 5 on Aug 29, did test again, got 5 again)
GH = 6 (was 8 on Aug 29) will do test again when done writing this

Again, the 8 young ember tetras, who I’ve had for almost a month (cycled tank BEFORE I added them), are all acting completely normal, continuing to grow and deepen their orange color. The cardinal is at least a year old ans aside from listing is actively eating, acting normal, hangs out in his fave parking spot a little more often maybe. Only other thing is about a month ago the red in his stripe disappeared from kinda just behind his head. It still goes to his nose and is vibrant from the missing spot all the way to his tail. Blue stipe looks the same as ever. I’ll try to load picks of him.

Any ideas what I should do? I was going to tie a couple of the new plants to a new piece of wood (that heavy wood that starts with an m; forgot the name) that I bought from my lfs. Now not sure but the plants really need out of their little pots.
Pics…
Trying to load a video I just took of him. He’s worse again but swimming around after I put a little more smashed peas in the tank (that’s what you see floating around in the water). Darwin, my cardinal

 

My advice is fast the tank for longer. I see you did 10/6 to 10/8. Do four days. They will be fine. They will be totally fine with a few days off. I feed mine every 3–4 days now (used to feed every day and it created algae etc etc). I felt bad at first but it’s way better for the tank and the fish. The fish needs to stay upright for more than one day before he eats again.

 

Will my young embers be ok without food for that long?

 

Anybody else? Agree or no? Don’t want to be the final word!!

 

I’ll plan on fasting them. Darwin, the cardinal, was my first fish and he’d had a hard life so I want to do what is right for him.

The embers are very healthy. I’ll just keep an eye on them. What should I watch for if they get too hungry? I’ll think about low stress ways to separate him if I need to feed them embers… He parks in a corner so I may be able to slide a piece of plexiglass in just long enough to give a little food for the embers???
I’ll keep check back here too. Y’all have helped me with so much!

 

My advice is fast the tank for longer.

Why fast in the first place? This makes no sense.
Actual swimbladder infections are not as common as people think outside GOLDFISH. It's an endlessly regurgitated misconception.
Usually buoyancy problems are connected to other problems, in this specific case, the fish is old and probably has organ deficiencies.

The fish is visibly old and developing symptoms in correlation to exactly that. It also is developing a growth on its back. I presume the growth pushes on the swimmbladder on the inside causing the tilting.

Fasting fish for 1-2 days a week is fine, in some cases 3 fast days are also ok, if the feedings inbetween are sufficiently sizeable with live or frozen food. They should not be fasted for several days in a row, except eventually in a vacation situation.
As there are juvenile fish in the tank there should at most be 1 fast day a week.

He parks in a corner so I may be able to slide a piece of plexiglass in just long enough to give a little food for the embers???

Spare the fish that additional stress situation. Just feed the others.

 

He has gotten worse… almost completely sideways and working harder than usual to swim. Seems like MacZ might be right. Should I euthanize him? I don’t have clove oil tho.
Figured I might as well feed him as he’s enjoyed that in the last few days. But he can only catch a little as he can’t navigate well Can anyone message me on what to do please?

 

Yeah, that one is not going to bounce back.

The next best thing to do with such a small fish would be the refridgerator (NOT freezer!) method. Take an opague container with tankwater, the fish in it, shut the lid so it's dark inside, let it cool down in the refridgerator. In the dark the fish should be calm, then the temp slowly dials down, as does its metabolism until it just seizes to work.

Not the best method, and only if more humane methods are not available. I would usually prefer the recommended ones, but the fish is too small for a clean cut or blunt force.

 

Thank you, MacZ. Called around and didn’t find clove oil so I’ll do that. Should have bought some before just as a precaution. Will do so for the future. Thought he was only a year old . In his memory I’ll be more prepared in the future. Will teach it to my students too. They will be so sad to hear what happened.

 

Depending on the season bout 50-75% of this species are still wild caught. So your fish could be between 2 and 4 years old already.

 

I am So happy I had the OG MacZ to jump in! I was totally off base in this case AND found out I should be feeding way more often! Love this site bc when ya don’t know you get those who do to help! Yay! I do have a quick question: why do you think fasting the cardinal like the OP did a few times helped a little? Or was that just coincidence? I can see me making the food mistake bc it appeared to work to fast!

 

why do you think fasting the cardinal like the OP did a few times helped a little? Or was that just coincidence?

Indeed coincidence. It's often the case that people do something they are told should be helping and interpret minimal improvement as prove of that. A reason I try to not foster unrealistic hopes.
Unfortunately I know this phenomenon we see here and that short term recovery and decline alternate a few times, getting worse each time until there is no recovery anymore at all.

 

Indeed coincidence. It's often the case that people do something they are told should be helping and interpret minimal improvement as prove of that. Unfortunately I know this phenomenon we see here and that short term recovery and decline alternate a few times, getting worse each time until there is no recovery anymore at all.

Yes makes a lot of sense. Wishful thinking likely too ya know? Or would be on my part.

 

Yes makes a lot of sense. Wishful thinking likely too ya know? Or would be on my part.

Kinda, I don't want to call it that (I was close to writing it). More like placebo effect by proxy.

 

Thanks again for your help! This site is amazing. My students thought it was cool that MacZ is from Germany and helped with our Darwin. They miss him but feel proud for giving him a great home for his last couple months - lots of stuff to swim around and hide in, a growing group of live plants and some fishy friends.

RIP Darwin! Thank u for what we learned from you. You have a forever place in my heart as you were my first fish and oh so handsome ❤️

 

Indeed coincidence. It's often the case that people do something they are told should be helping and interpret minimal improvement as prove of that. A reason I try to not foster unrealistic hopes.
Unfortunately I know this phenomenon we see here and that short term recovery and decline alternate a few times, getting worse each time until there is no recovery anymore at all.

agree witg MacZ again.

Wanted to add : Don't ever add clearly sick fish to another tank with (healthy) fish.

In my opinion the fish showed signs of Columnaris bacteria (weakened) but what disease / issue at all, don't risk other fish this way.

 

agree witg MacZ again.

Wanted to add : Don't ever add clearly sick fish to another tank with (healthy) fish.

In my opinion the fish showed signs of Columnaris bacteria (weakened) but what disease / issue at all, don't risk other fish this way.

Darwin was acting completely healthy when I moved him to my ember tank; same behavior since mid-June. The symptoms didn’t appear until a week after I moved him.

Trying to figure out why you thought this, I reread my original post. When I said that he seemed “better” after moving him to the ember tank, I meant more confident and relaxed since the embers are mellow and his old tank mates were hyper platies that used to rush around him and sometimes bump into him.

Do I need to worry that the embers may have caught what he had, the bacteria you think he had??? They all seem completely fine other than three are growing slower and two faster than the others but that could easily be individual variation. All eight are eating, swimming, and behaving normally. Is there anything I can do preventatively (hopefully)? Or at least a medication to have on hand in case? Is there something to watch for?

 

Darwin was acting completely healthy when I moved him to my ember tank; same behavior since mid-June. The symptoms didn’t appear until a week after I moved him.

Trying to figure out why you thought this, I reread my original post. When I said that he seemed “better” after moving him to the ember tank, I meant more confident and relaxed since the embers are mellow and his old tank mates were hyper platies that used to rush around him and sometimes bump into him.

Do I need to worry that the embers may have caught what he had, the bacteria you think he had??? They all seem completely fine other than three are growing slower and two faster than the others but that could easily be individual variation. All eight are eating, swimming, and behaving normally. Is there anything I can do preventatively (hopefully)? Or at least a medication to have on hand in case? Is there something to watch for?

Misread that. But there was only one cardinal from the start? Columnaris affects fish when weakened / stressed.

 

Misread that. But there was only one cardinal from the start? Columnaris affects fish when weakened / stressed.

OK, thanks for that info. I ordered the meds for it just in case. I'll keep an eye on the embers though they seem very healthy and don't have any reasons to be stressed.

Yeah, long story on the cardinal; I'll summarize here... I was given just him and a pleco in a tank with just ravel I tried getting him friends but they all died within a week of putting them in the tank. Did also get fake plants and decor to give them both places to hide. Everyone was telling me that cardinals were only for more experienced hobbyists and that a 10g was too big for a school. So I got the three platies since they are a beginner fish and would at least be company if not schooling buddies.

Thinking back, I think the cardinal was also given to the teacher that had him before me. So I'm wondering if it was the last one someone had after all the other cardinals in the tank slowly died off??? Since Darwin was apparently quite old, that could explain it. Thus me being happy that we gave him a better end to his life even if it wasn't in a school.

 

looks like a neon tetra, not a cardinal.

 

looks like a neon tetra, not a cardinal.

Nope, definitely a cardinal.

 

Misread that.

I wrote it poorly. Could totally understand why you got that idea.