Fish loosing slime coat

[SLS_23]

Have you tested your water?

Yes

If I did not test my water...

1. ...I recognize that I will likely be asked to do a test, and that water tests are critical for solving freshwater health problems.

Do you do water changes?

Yes

What percentage of water do you change?

41-50%

How frequently do you change your water?

Every two weeks

If I do not change my water...

1. ...I recognize that I will likely be recommended to do a water change, and water changes are critical for preventing future freshwater health problems.

Hi, does anyone know what to do? My fish are losing their slime coat. All water readings are fine. I change the water ½ every 2 weeks. As soon as I saw it yesterday I changed ¾ of the water and added salt, but I couldn't save 3pcs of B. tigrinum. Anyone know what it is? Will it save the other fish or would it be better to euthanize them all as a precaution? Thank you

 

[Milingu]

Looks like oodinium - velvet disease.

 

[SLS_23]

Looks like oodinium - velvet disease.

Thank you for the reply, it is similar in appearance, but it doesn't fit the course of the disease at all. The fish got it completely all in the aquarium in one no(except 3x butterfly fish) and they are dying terribly fast. I check the fish every day, especially the brachyplatystomas, but they died first. Before I found the first brachyplatystoma, I didn't discover any symptoms.

 

[SLS_23]

So the rest of fishes is dying too. I tried fmc and it didnt help.



View attachment 1000013245.jpg

 

[shern]

params? kinda feels like ammonia burn?

 

[danotaylor]

params? kinda feels like ammonia burn?

Or a pH crash
Any new additions recently? Potential toxins from new decor?
I had a friend install a brand new universal rocks background on a well established tank. Everything was dead the next day.
I recommend having fresh charcoal on hand to add to the filter in the event of mystery deaths incase of inadvertent toxins getting into the tank. Sometime local councils change there water treatment routine or do something different as a cleanse that can kill fish despite conditioning. Charcoal can help mitigate losses.
Sorry mate. That really sucks for ya

 

[thiswasgone]

If I had to take a guess, a 24hr killing with slime coat sloughing off like this after a water change will either be (in order of most likely):

1) Chemical burns from either chlorine or chloramine
2) A severe festering bacteria infection that hit hard due to a stressor(s) (maybe the water change)
3) Severe external parasite infection bloom due to stressors similar to above

Without knowing the underlying cause I have no real direct solution I can give you outside of doing a shotgun treatment if it is caused by a disease and not something like chlorine burns.

For options 2 & 3 the only 100% way to know if it's not is to do a slime examination with a microscope. It's also completely possible you did everything right and it's none of the above. Do you run on well water or use city water? Did you make any changes/additions recently? There could be endless causes but if you still have surviving fish I would bring them over to a separate tank/container with fresh treated water and either do a shotgun treatment of their feed (if they still eat) or their water. Alternatively get 2 separate tubs and run 1 clean with fresh treated water and the other use as a medicated bath depending on what medication you have on hand.

Medicated feed is typically better compared to water treatments.