Black Phantom Tetra- are they sick?

[Sondra Bradshaw]

Hi all! I am newer to the hobby, about 9 months in. I currently have 4 panda corydoras (had 5 as of this morning... hence why I'm here) and 7 black phantom tetras. Black phantom tetras were added to the tank about a week ago. So yes, I have new fish... the one panda Cory passed this morning, however, he was ALWAYS tinier than the rest and just wouldn't grow. All of the others had thrived and were doing really well and this one stayed the same. I was told he was a runt. Then he randomly took a turn for the worse last night and passed away sometime late last night and early this morning. I feel he died mainly to being a runt but I want to be sure as I did just add these black phantoms and to me, some of their behavior is off and a couple of their tail fins look almost translucent and I'm not sure if that is normal as I have only owned these guys for two weeks. 
 

I was to go on vacation at the end of June with my fiancé's parents but they called a couple days after receiving the black phantoms that we are going on the 3rd and will be gone until the 8th. If treatment is needed, I would really like to try and get things under control before I go. Any help or advice is appreciated. 
 

tank parameters 

36 gal bowfront 76 degree f 

PH 7.4

ammonia 0

nitrite 0 

nitrate 5 

kh 4dkh 

GH 10dgh 

weekly 25% water change with weekly fast as well as a frozen treat (chopped bloodworm, brine shrimp) once a week. 

[Tony s]

your water looks good. are the rest of your corys showing any symptoms. sluggish, not eating? the tetras may have brought in something, but if there are no symptoms, probably not. sometimes we just lose animals. most of the time we're just guessing as to why. if no symptoms, just keep an eye out for now. if you see something, let us know.

[Colu]

Any rapid breathing hanging out near the surface lethargy flashing spitting food out sunken belly white stringy poop red Gill's 

[Sondra Bradshaw]

On 5/30/2024 at 4:01 PM, Tony s said:

your water looks good. are the rest of your corys showing any symptoms. sluggish, not eating? the tetras may have brought in something, but if there are no symptoms, probably not. sometimes we just lose animals. most of the time we're just guessing as to why. if no symptoms, just keep an eye out for now. if you see something, let us know.

@Tony s

 

hey there! Thanks for the response. I haven't noticed anything abnormal with anyone else besides the phantoms seem to dart at each other often but doesn't seem to be leaving damage. I have noticed their fins lose color at times (phantoms) but overall are very active and all come to the front of the tank when they think I'm feeding them. Cory's are as active as usual, even more so now that my runt is gone, even. The runt would try and keep up a lot but just struggled. Always has. And seemed to have been more stressed than the rest when initially released into the tank. My heart is broken for the guy, and I'm just anxious they're sick. However I do think the tetras are stressed due to new environment but I think things are going well. 

On 5/30/2024 at 4:10 PM, Colu said:

Any rapid breathing hanging out near the surface lethargy flashing spitting food out sunken belly white stringy poop red Gill's 

@Colu

nope, haven't noticed any of that. The tetras sometimes do that but I believe due to something being too big that the corys end up eating as they have no issue with littler things. 

[Tony s]

On 5/30/2024 at 4:52 PM, Sondra Bradshaw said:

I think things are going well

Sounds very good. You can always @   colu if you have serious concerns about any diseases. He's our expert 🙂

[Colu]

Nothing jumping out that would indicate you have a disease present in the tank I would just monitor make sure everyone eating ok no abnormal behaviour if you notice anything out of the ordinary give use an update