Plot thickens: ulcers, lateral line involvement, white spots, nodules, sunken spine--ember tetras,pygmy hatchetfish, pygmy corydora, celestial pearl danio

[VernalPool]

Edit:  Last paragraph: " .....realistic and safe way to (clean) this planted tank....."

[xXInkedPhoenixX]

Oh my, I'm so sorry. Your poor fish. In my opinion with what you describe, the pics and images and further research I've done on Neon Tetra Disease it really does appear to be that. Is there anyone in the tank at all that does not appear to be suffering the symptoms? If so pull them if you can and put them in a separate container if possible, as it seems- IF THE DIAGNOSIS IS CORRECT- there is no saving the infected fish as it is fatal and no known cures. I hope others offer opinion for consensus. I think you may already suspect that is what it is too. 

Until you decide what to do and as long as you feel there is fight left in the fish you can keep them in their with the meds if it's possible it's something else. 

You will need Clove Oil to euthanize fish. It's the most humane way to do it when you are ready and sure the fish aren't going to make it. You can put them in a container of water and add a drop, sometimes more (google, youtube search etc) to put them to sleep first, then basically you overdose them on it. 

As to eventually sanitizing the tank. Personally I'd toss everything inside it and anything associated with it. 

I've never dealt with anything so fatal so I have no idea if plants can be sanitized. I'm not sure if a Hydrogen Peroxide dip would kill off this disease or not. 

I'd bleach the tank using hot water, a few times. Rinse many times with hot water and leave in the sun for several days or weeks until it was bone dry. 

The shrimp and snails....are they with your other fish now? 

[Colu]

I agree I think you dealing with neon tetra disease it can affect angelfish danios and some species of barbs the names a bit deceptive unfortunately they no cure and your fish will continue to decline. As for sterilising the tank if it comes to that I would get rid of all the plants substrate an wood or rocks in the tank bleach it as  @xXInkedPhoenixX suggest and also I would clean it with isopropyl alcohol as well leave it  dry for a month when you fill it up for the first time you could also add a high dose of aquarium salt 5-10 table spoon for 1 gallon that will help to kill any possible remaining pathogens after that I wouldn't put fish in that tank that can get neon tetra disease 

Edited November 29, 2021 by Colu

[xXInkedPhoenixX]

Maybe this tank will just be a shrimp and snail tank in the future if you keep it. These can be very satisfying tanks to have too. 

[VernalPool]

@Colu@xXInkedPhoenixX Neon tetra disease was the answer I expected, but not the one I wanted.  Since all fish show some sign of disease, I will euthanize them all tonight and begin breaking down the nano tank, etc.  Tomorrow, I'll move the snail and 2 Ammano shrimp to a 2.5 gallon I have empty and try to come up with a better plan for them.  Looks like I'll have an extended break ahead of me.  ☹️

 

 

[xXInkedPhoenixX]

I'm so sorry friend. The whole forum is here to help you when you're ready to rebuild and/or need support. 

I know it can be discouraging sadly not one of us here is free from some sort of or several tragedies. Even @Cory says, expect that you will have fish die in this hobby. 

If you haven't already watched it Cory made a video about Neon Tetra Disease: 

 

[Colu]

I wouldn't euthanize your pygmy Cory's they won't get neon tetra disease  @VernalPool

[xXInkedPhoenixX]

I agree with @colu as I said in my previous post, pull anyone who doesn't look sick.