My fish are dying help I don’t know what to do

Help! I have a 20 gallon planted tank, it had 4 cardinal tetras in it, recently I added 3 more tetras and a red honey gourami. Suddenly all the tetras began dying, now two are left, even the large ones iv had since the very beginning are dying, I don’t know why, iv tested water conditions they are good. I noticed the gourami pecks at the dead bodies of the fish, and my living ones seem weak and banged up, could it be killing them!?

 

Help! I have a 20 gallon planted tank, it had 4 cardinal tetras in it, recently I added 3 more tetras and a red honey gourami. Suddenly all the tetras began dying, now two are left, even the large ones iv had since the very beginning are dying, I don’t know why, iv tested water conditions they are good. I noticed the gourami pecks at the dead bodies of the fish, and my living ones seem weak and banged up, could it be killing them!?

What exactly are your water parameters, how long has the tank been running and how often/how much water do you change?

 

I would separate them… if your water is good… I would say your tetras are being bullied

 

I would remove the dead ones right away so they don't release any ammonia or whatever killed them.

 

I can tell from the photo that the Gourami you have is actually a Thick Lipped Gourami, which are almost always mislabeled as Honey Gourami. (If I had a nickle for every time I've seen a Thick Lipped be called a Honey, I'd have enough money to buy a new tank!) That being said, I doubt it's the Gourami's doing. Thick Lipped are generally peaceful and mellow. (Though I can't completely rule it out as a cause.)

I think it's much more likely that the new Tetras brought in a disease. I can't really pick up any clues from the photograph unfortunately. Some more photos would be great if you can get them, and filling out the emergency template really helps us get to the bottom of things quickly!