Sick Tetra Glofish

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Atlanta9

Aquarium Advice Newbie
Joined
Jun 28, 2024
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4
Location
Atlanta
Hi there, can someone help with a diagnosis please? I've gone through the Handbook of Fish Diseases flow chart and I'm still not sure.

Set up:
37 gallon bowfront tank
SunSun canister filter
Fully cycled tank, ammonia and nitrites = 0, Nitrates = 5, pH = 7.5, temp = 75
Tank running for about a year with regular water changes
Current stock: 6 tetra glofish
Nothing new added

One of my blue glofish has a sudden onset of a disease or injury (see pictures and video). He is a bit lethargic compared to the others but seems to be eating fine as of this morning. He's swimming normally and not at the surface gasping for air.

I did have 6 otos when I first set the tank up a year ago, but they all died one by one over the year and I was never sure why. They got plenty to eat and never looked sick. It's possible that they had a disease I didn't recognize and the glofish caught it by nibbling on a dead oto before I could get it out of the tank. The last oto died about a month ago.

Any help would be most appreciated. Thanks!

Video of sick fish:
 

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Otos are not really good fish for new aquariums. You say they had plenty of food to eat but that doesn't mean they were eating it or it was the correct food to keep them healthy. ( For example: Put a man in a store full of candy and he will have plenty to eat but it won't keep him healthy. ) I would not read too much into their demise due to the age of the tank.
Your Tetra appears to have an infected injury. The pectoral fin looks like it is missing and the flesh around where it was is rotting. This could have happened by one of the other Tetras biting it ( they do that sometimes) and then the wound got infected or it could have come in with an infected fin and it just got worse. As long as the fish is still eating, there is a chance you can save it. It should be medicated in a separate hospital tank with an antibiotic. If you don't have a separate tank, you can use a bucket or tupperware container or anything where you can measure the exact amount of water being medicated. Since most medications are designed for 10 exact gallons of water, using something divisible into 10 helps so that you can adjust the amount of medication as needed. You will need to know what your water's pH and GH are to determine the best medication to use.
 
Thank you for your response. Would you share why otos are not good in a new tank? I did feed them algae wafers a few times a week plus a slice of blanched cucumber every other week.

Thank you for the advice about my tetra. I'm not seeing that the pectoral fin is missing (see photo), but an infected bite makes sense. I have a 5 gallon bucket that I use as a quarantine tank. Is there a decision guide for what antibiotics to use somewhere on this forum?
 

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Thank you for your response. Would you share why otos are not good in a new tank? I did feed them algae wafers a few times a week plus a slice of blanched cucumber every other week.

Thank you for the advice about my tetra. I'm not seeing that the pectoral fin is missing (see photo), but an infected bite makes sense. I have a 5 gallon bucket that I use as a quarantine tank. Is there a decision guide for what antibiotics to use somewhere on this forum?
Otos do better on biofilm and algae more than solid foods and a new tank will not have enough biofilm in it to feed them. The rest of the foods you fed might have kept them alive but was not nourishing them.

In this pic, I see the fin too. I did not see it clearly in the other pics or video. This is an infection. The flesh is rotting and subject to the other fish attacking it. Unfortunately, there is no " decision guide" to antibiotics anywhere that I know of outside of the company websites that manufacture the meds. There are antibiotics that work better in higher pH water and some that work better in low pH water and some combinations that will work in more neutral pH water. Same applies to hardness levels. Sadly, there are very few if any products that explain this on their packaging. :( I spent over 45 years working with meds in the tropical fish industry including doing sensitivity cultures to know exactly which meds would work best under " this or that " situation. The list of meds and combinations is too long to list them all and not all of the meds are still available everywhere and there are new ones coming on the market all the time just to make things more interesting. :rolleyes: In your case, if you have a pH below 7.0, use Nitrifurazone. If your pH is above 7.2, use Kanamycin ( easily found in Seachem Kanaplex). If your pH is between 6.8 and 7.2, use these two meds together but you will need to follow the redosing and water change schedules of them both.

I will say this: In your case, this fish is going to take some time ( probably months) to heal and would be better off in a separate quarantine tank with filtration and a complete setup after it finishes with the medicated period. (All you will need in the bucket while medicating is an air stone and possibly a heater if your room temp is too cool. No need to cycle a filter for it as these meds will affect or suppress the nitrifying microbes. ) Months in a small bucket will probably not do the fish any good. So you need to consider all this before trying to save this fish vs euthanizing it and/or replacing it.

Edit: Just reread your opening post and see your pH is 7.5 so if you do decide to medicate, use the Kanaplex. (y)
 
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Thank you for such helpful advice. The fish died before I could even get it into quarantine, but it seems like that was for the best overall. I took a picture postmortem. Does it still look like an infection? My husband was worried that it might be fish TB.
 

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Thank you for such helpful advice. The fish died before I could even get it into quarantine, but it seems like that was for the best overall. I took a picture postmortem. Does it still look like an infection? My husband was worried that it might be fish TB.
Unfortunately, because the area does not look like TB in the other pics, it's less likely in the post mortem pic. The real issue with fish TB is when you have cuts or abrasions on your hands or arms that get submerged in your water. That's how it transfers from fish to human. It's always best when it comes to dead fish to be extra cautious and not handle them, wash your hands or any area that may have gotten wet really well and sanitize your net and bucket or containers that were used with this fish so help ensure whatever it was does not get spread to other fish you use these equipment for. Because fish TB is rampant on many fish farms, it's always a possible diagnosis. The only way to know for sure is to have the fish professionally analyzed but by the time you would get a result, the damage would already have been done. Better to be careful than to be sorry. ;) (y)
 
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