Swordtail with Popeye. Treatment options??

[ddrojass]

Hello, 2 days ago I noticed one of my female swordtails was laying on the bottom, didn't think any of it because it was kinda late so I assumed she was sleeping, yesterday I went to feed them and my female swordtail was in the bottom hiding, with a really big eye and red underneath it. I immediately panic and went to my LFS to buy dechlorinator, NO3 test and I picked up some AmGuard. I added AmGuard to my main tank (I have no test because there are none in stock) in case and I quickly putted together my 5gal hospital tank (heater, hiding spot and sponge filter) dosed aquarium salt per instructions and added KanaPlex per instructions, and transferred my swordtail.


1~What type of fish is afflicted?
1 female swordtail with unilateral Popeye

2~What are your tank parameters (ammonia, nitrites, nitrates, temp, pH)?
Am: 0ish (i don't have a test because there are none in stock)
NO2: 0
NO3: 20ish
Temp: 78ºF
pH: 5.2

3~ How large is the tank? How long has the tank been set up?
its a 25gal tank. 10 months

4~What type of filtration are you using?
SunSun HW-302 external canister filter 265GPH
Aquael 500 UV filter (unsure of GPH)

5~How many fish are in the tank? What kinds of fish are they and what are their current sizes?
1 corydoras panda(haven't found more to form a school)
6 corydoras elegans (substitute school for my panda)
2 German Blue Ram (a couple)
2 Male swordtails (bought 3 females, but one turned to be a male)
2 Female swordtails (one of them is sick)
1 Swordtail (1.5 month old)
5 Neon Tetra (had more, but been slowly dying I think they have NTD due to patches)


6~When is the last time you did a water change and vacuum the gravel? How often do you do this? How much water do you remove at a time?
Last water change was on Sunday and vacuum on Saturday.
once a week (every sunday)
about 20%

7~How long have you had the fish? If the fish is new, how did you acclimate it/them?
5 months

8~Have you added anything new to the tank--decor, new dechlorinator, new substrate, etc.?
no, but I did remove the driftwood in the tank so it was kinda bare and lacking hiding spots

9~What kind of food have you been feeding your fish, have you changed their diet recently?
Corys eat Tropical welsh gran, the rest eat either prodac flakes, hiker micro pellet or NLS probiotix pellet. (they prefer prodac, so I have been unable to switch to a better diet with hiker or NLS permanently)


Photo of the eye
https://imgur.com/1QWQT1E

 

[DeepAsHadal]

Your ph 5.2 is really low. is that right? Do you use Amguard for normal water changes?

I'm new to fishkeeping, but this site mentions popeye may be from many things, including gram positive bacteria and could be treated with erythromycin. I'm sure it could be any of a million things though.

https://aquariumscience.org/index.php/10-3-8-popeye/#:~:text=In%20%E2%80%9CPopeye%E2%80%9D%20the%20fish%E2%80%99s%20eyes%20bulge%20out.%20Popeye,Mardel%20Maracyn,%20Thomas%20Labs%20Fish%20Mycin)%20or%20penicillin.

Probably overthinking this, but looking over some of the information on popeye, it's mentioned gram positive bacteria can also be a cause of False Neon Disease.
FTD starts halfway down the page. FTD can be hard to differentiate from NTD, but I don't know much about either.
https://www.aquarium-pond-answers.com/2007/02/neon-tetra-disease.html#:~:text=I%20will%20note%20it%20is%20common%20to%20confuse,generally%20caused%20by%20less%20common%20gram%20positive%20pathogens.

https://www.honeygourami.com/how-to-care/aquarium-fish-health/false-neon-disease/