Help! Weird White Fungus Killed Two Bettas

Hey! I need some help.

For christmas I got a betta fish, and made sure to give it all the essentials to a good aquarium (5 gallons, heater, filter, etc), but about a month in, I found my fish completely covered in a weird white fungus. This stuff looked more like hair or fluff than mold. The fish was, of course, dead, and I was devastated. I assumed that it was something that the fish had caught while at the pet store (he came in a TINY half gallon bowl and was very unhealthy).

However, this is where it gets weird. I decide to buy a second betta, and get this one from a completely different pet store. He seems to be doing well until, very suddenly, I find him encased in the same fluffy fungus. This fungus is more than a half inch long and completely loses its shape when taken out of water.

I really want to get a new betta because I love the little animals and I have all the equipment, but I'm too scared to get another one until I know what weird fungus killed the other two and how I can prevent it.

I've done a lot of research but found nothing that looks like the stuff that killed my fish.

Please help!! Thanks

 

If you have a photo that would really help. I'm thinking maybe columnaris?

 

If you have a photo that would really help. I'm thinking maybe columnaris?

Hey! I need some help.

For christmas I got a betta fish, and made sure to give it all the essentials to a good aquarium (5 gallons, heater, filter, etc), but about a month in, I found my fish completely covered in a weird white fungus. This stuff looked more like hair or fluff than mold. The fish was, of course, dead, and I was devastated. I assumed that it was something that the fish had caught while at the pet store (he came in a TINY half gallon bowl and was very unhealthy).

However, this is where it gets weird. I decide to buy a second betta, and get this one from a completely different pet store. He seems to be doing well until, very suddenly, I find him encased in the same fluffy fungus. This fungus is more than a half inch long and completely loses its shape when taken out of water.

I really want to get a new betta because I love the little animals and I have all the equipment, but I'm too scared to get another one until I know what weird fungus killed the other two and how I can prevent it.

I've done a lot of research but found nothing that looks like the stuff that killed my fish.

Please help!! Thanks

Sounds more like a sapronalgia (may have spelled that wrong) infestation. Did you cycle? Water parameters? Water change schedule?

 

Did you disinfect the tank before adding your new fish? Whatever killed the first one probably stayed in the tank if you didn't, and is why your new fish got it. You'd be surprised at how long spores or bacteria can stay in a tank even without hosts.

 

If you have a photo that would really help. I'm thinking maybe columnaris?

Sorry, I didn't get any photos, as the fuzz only showed once it had killed the fish, and it made me queasy to look at them... However, Columnaris seems too close cropped and localized; the stuff that killed my fish was really long, fluffy, and completely surrounded them.

Sounds more like a sapronalgia (may have spelled that wrong) infestation. Did you cycle? Water parameters? Water change schedule?

Sapronalgia seems fairly similar... The issue is that I can't find any funguses that completely encase the fish like the stuff that killed mine did. It looked almost like a cocoon, very eery.

Regarding water conditions, I didn't cycle the water for the first fish because he had been in a tiny little bowl for more than a week as I waited for my tank to arrive (the fish was a surprise gift, otherwise I would have prepped better) and was very stressed in the bowl, so I thought it best to get him out of it ASAP. I cycled the water for the second one though. I didn't think to test the parameters of the water, but the temperature was around 75 degrees F and I had a sponge filter in. As for water change, I had done half water changes every two weeks and was planning a full change once the month was over but neither lasted long enough...

Did you disinfect the tank before adding your new fish? Whatever killed the first one probably stayed in the tank if you didn't, and is why your new fish got it. You'd be surprised at how long spores or bacteria can stay in a tank even without hosts.

You're right, I did a full water change and scrubbed all the decorations but didn't think that the stuff would be so persistent. The tank, sand, and deco have been sitting, dry, in open air for a couple months now, would it be safe to add a fish again? If not, how should I go about disinfecting everything?

Sounds more like a sapronalgia (may have spelled that wrong) infestation. Did you cycle? Water parameters? Water change schedule?

Oops! Meant half change every week

 

Sorry, I didn't get any photos, as the fuzz only showed once it had killed the fish, and it made me queasy to look at them... However, Columnaris seems too close cropped and localized; the stuff that killed my fish was really long, fluffy, and completely surrounded them.


Sapronalgia seems fairly similar... The issue is that I can't find any funguses that completely encase the fish like the stuff that killed mine did. It looked almost like a cocoon, very eery.

Regarding water conditions, I didn't cycle the water for the first fish because he had been in a tiny little bowl for more than a week as I waited for my tank to arrive (the fish was a surprise gift, otherwise I would have prepped better) and was very stressed in the bowl, so I thought it best to get him out of it ASAP. I cycled the water for the second one though. I didn't think to test the parameters of the water, but the temperature was around 75 degrees F and I had a sponge filter in. As for water change, I had done half water changes every two weeks and was planning a full change once the month was over but neither lasted long enough...


You're right, I did a full water change and scrubbed all the decorations but didn't think that the stuff would be so persistent. The tank, sand, and deco have been sitting, dry, in open air for a couple months now, would it be safe to add a fish again? If not, how should I go about disinfecting everything?


Oops! Meant half change every week

Yeah from your description definitely sounds like sapronalgia outbreak, here is my reasoning

Sapronalgia can only grow on dead tissues ✅

Sapronalgia resembles hair like structures and can grow like a fluffy wad ✅

Sapronalgia can start to attack fish if infestations get out of hand ✅

Columnaris can only survive on a living host
Host was dead

Columnaris is centralized and normally appears in oblong lesions or compact white “mold” like sores
Had a hairy fluffy appearance not lesions


Over feeding can allow infestations to get out of hand, just like detritus worms, or seed shrimp, sapronalgia is a natural micro fauna that can live peacefully in your aquarium, only when these micro fauna take over do they cause issues. Reduce decaying matter, increase mineral cations, keep ph above 6.5, and be thorough with water changes, maybe even up filtration a bit with a stronger pump.

Edit: realized the correct spelling is “saprolegnia” not “sapronalgia” so I was way off the mark on spelling sorry XD