How long does fish tb last in an empty tank?

[mapleleaf218]

I have a question about the death of some of my goldfish in the past. I had a common goldfish, fantail, and oranda that all died with a bent back, and I still am not quite sure why they became like that. At first, I thought it was nitrate poisoning (or a shock from a drastic change in nitrates), but doing small water changes didn’t help. I did a little bit more research, and apparently it also could’ve been fish tb?? 
Now, here’s my problem: the main tank that those goldfish died in has been empty for over 8 months now, and has live plants in it right now. I plan to add several platies (which I am treating in my quarantine tank right now) to this tank in several months time, and now I am not so sure about it because I didn’t do a thorough cleaning (sterilizing everything) of the main tank after the fish died. If those goldfish actually had fish tb, then do you think the disease would still be present in the tank after it being empty for almost a year? Should I completely clean out the main tank and sterilize everything and restart the cycle just to be safe? I am hesitating to do so because my live plants have just started taking off, and I don’t want to disturb my substrate-planted plants too much.

[Guppysnail]

Mycobacterium can infect humans and is serious business. There are no tests that can be performed on a living fish to determine if that is what it is. The risk in my opinion is to great. I’ve heard several places that it can use mollusks and worms as intermediary hosts until fish are present. Hydrogen peroxide is more effective at killing all strains of mycobacterium than bleach. I personally would scrap the entire setup plants substrate media and anything I could not soak in peroxide but that is my opinion due to it being my health also at risk not just fish. Best of luck. 

[Torrey]

On 1/8/2022 at 4:17 PM, mapleleaf218 said:

I have a question about the death of some of my goldfish in the past. I had a common goldfish, fantail, and oranda that all died with a bent back, and I still am not quite sure why they became like that. At first, I thought it was nitrate poisoning (or a shock from a drastic change in nitrates), but doing small water changes didn’t help. I did a little bit more research, and apparently it also could’ve been fish tb?? 
Now, here’s my problem: the main tank that those goldfish died in has been empty for over 8 months now, and has live plants in it right now. I plan to add several platies (which I am treating in my quarantine tank right now) to this tank in several months time, and now I am not so sure about it because I didn’t do a thorough cleaning (sterilizing everything) of the main tank after the fish died. If those goldfish actually had fish tb, then do you think the disease would still be present in the tank after it being empty for almost a year? Should I completely clean out the main tank and sterilize everything and restart the cycle just to be safe? I am hesitating to do so because my live plants have just started taking off, and I don’t want to disturb my substrate-planted plants too much.

When I worked in a pet store during college (my kids would add, back in the age of dinosaurs), the owner had been hospitalized with a mycobacterium infection. She was understandably adamant about no more goldfish and sterilizing everything... and didn't have enough liquid assets to scrap everything in the fish room and start over.

She bought a UV sterilizer instead. The goldfish tanks were cleaned out with H2O2 first, then with 91% isopropyl alcohol, and finally with vinegar. She said that was the doctor's advice. @Odd Duck may have more accurate information. 

We ran the UV sterilizer on each section of tanks for 4 days, and then moved to the next section (tanks were arranged by biotope needs, and shared filtration for each biotope section) for 4 days, until back to the beginning section to repeat the process. 

We never had another ich outbreak, and stopped losing 30% of the shipments to disease. She ultimately bought a 2nd UV filter for the Q/T room and all incoming shipments were in Q/T for 2 weeks of UV treatment. 

My scope of practice for people is limited to birth work, so I don't know if her protocol was sufficient to keep people or fish safe. I do know that for the 80's, it was as advanced as I ever heard for the time.

[Odd Duck]

@Mapleleaf, IF your fish truly had a Mycobacteria infection, it’s not something that can be eradicated short of full disinfection of the system, like soaking everything in bleach, kind of disinfection.  It can’t be cured and it’s extremely difficult and expensive to treat, and since it can’t be eradicated in a living fish, it will eventually reinfect others.  It is also zoonotic, meaning it can be transmitted to people or other animals/fish.  It could even be aerosolized via any bubbling in the tank or it could be contracted in a non-respiratory form via any scratches or cuts exposed to tank water.  Immunosuppressed individuals are at much higher risk of contracting Mycobacteria (like with any other infection).

If it were my tank, and I was convinced it was a Mycobacteria outbreak in the tank, I would break it down and sterilize completely and very thoroughly, discard any plants into the trash, not into a compost heap.  Discard all substrate and wood.  Non-porous rock that’s not too textured can likely be disinfected appropriately with soaking.  Soak everything that might have touched the water in a dilute bleach solution for a full 10 minutes.  Use normal bleach, not the splashless kind (it’s less concentrated), and dose at 1/4 cup per gallon of water in a well ventilated area. You could run your filters on the tank with all media removed and discarded since they need to be disinfected, too.

Rinse everything extremely well, then rinse several more times.  Then soak everything in water with at least a triple dechlorinator dose for at least 30 minutes or more, with some water circulating.  Then maybe rinse and dechlorinate again, just to be safe.  No science behind that last step, but it’s what I’d do for mine.

All new substrate, media, plants, etc, and start over with your cycle.

Edited January 10, 2022 by Odd Duck
Add tag for OP.

[Torrey]

Thank you @Odd Duck, I am screenshotting your recommendations to add to my aquarium file.

Mycobacterium is no joking matter.