UV Sterilizer in Quarantine Tanks

[anodyne99]

Last week I had a betta die at 18 months, after a year of dwindling and progressive emaciation, ending with clamped fins and fin rot, then buoyancy issues. Over the course of the last 6 months I tried the med trio, then just Praziquantel, then Kanaplex, and finally plain salt. His fin rot stopped progressing but did not regrow, and otherwise he just continued to get sicker. I know the seller I bought him from later shared that they had an outbreak of m. marinum at their facility. They import from a breeder in Thailand and resell. I'm pretty sure that's what got my betta. 

He lived in his own tank with a mystery snail, but I have two other community tanks in the same room within 6 feet. I also used the same siphon in multiple tanks before I had ever heard of mycobacterium. I am anxious to do whatever I can to ensure  the safety of my other fish. I hate to think of just waiting to see if they succumb. 

I found Diana Walstad's article in which she recommends dealing with outbreaks by running a UV sterilizer in quarantine tanks and tanks with new fish. However, she doesn't share very specific info regarding their use. It seems she used sterilizers for about 6 months to control her own outbreak, but recommends 2-3 weeks in QT and then an unspecified amount of time once the fish are moved to the display tanks.

Does anyone have more detailed info? I understand that UV treatment seems to be the anecdotally supported mitigation strategy that comes up most often. I also keep hearing that the most important thing to do is support immunity, and that UV sterilizers can alter the healthy balance of bacteria in aquaria and thus weaken the fish. It seems like getting the right balance is important. How long is too long and tips you into doing more harm than good? 

If anyone knows of a well-designed study on the use of UV to mitigate outbreaks of  mycobacteria, I would be very grateful if you could share. If you have more detailed anecdotal experience with this to share, that would be welcome too! 

 

Edited April 5 by anodyne99
typo

[Colu]

UV sterilisers work by breaking the DNA chains of bacteria and viruses stopping them from reproducing if your UV  light is powerful enough UV light sude be a minimum of 1 watt per 3 gallons to kill bacteria and viruses if your betta had mycobacterium maximum I would steriliser all your equipment the tank he was in with a very high dose of 3% hydrogen peroxide leave it two dry then repeat the process then leave the tank running without fish for a minimum of 4 weeks with the uv steriliser running before considering adding new fish @anodyne99

[Nora Loves Corys]

Sorry to hear about your betta fish--they have such unique personalities, it is always sad when you lose them.

They are definitely a species of fish that can be plagued with mycobacteria. There are two nice articles here, both of which mention mycobacteria and UV filters:

> Dos/Donts for Fighting Mycobacteriosis

> A more in-depth discussion

I am not aware of any high-quality studies looking at how UV filtration on a hobbyist-sized aquarium helps with controlling mycobacteriosis. But anecdotally, I think it helps. I would not worry about it causing problems with bacteria in your biofilter; the bulk of these bacteria live in your filter on the media specially designed for them to colonize, and they are not just drifting around in the water column (which is what the UV sterilization is working on). Also, many commercial aquaculture operations use UV filtration on recirculating systems with no effect on biofiltration.

Hopefully this helps, and good luck with your community tanks. 🐟😎

[anodyne99]

Thank you so much, I look forward to checking out the information you've shared. I appreciate it!