Are these flukes on his fin?

[Tpepe321]

Have you tested your water?

Yes

If yes, what is your ammonia?

0

If yes, what is your nitrite?

0

If yes, what is your nitrate?

Under 20ppm

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

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.

I already treated my entire 125G with prazipro 3 days ago, hasn’t improved at all, if anything getting worse fast. Today he is having like tremors in his tail. I just tried some pellets with metroplex focus and garlic he won’t eat. Anything else I can do? I will try to treat with prazipro again

 

[Tpepe321]

Could this be anchor worms

 

[danotaylor]

Looks like fin rot exposing the dorsal & caudal rays. The only other thing is resembles is ammonia burns, but if your cycle is stable and without spikes, it looks like fin rot, which is bacterial.
I suggest salt @ 1tbsp/3 gal and large freq water changes for several weeks keeping the nitrates <5 if possible. Replace the salt to keep the concentration the same w your water changes

 

[Tpepe321]

Looks like fin rot exposing the dorsal & caudal rays. The only other thing is resembles is ammonia burns, but if your cycle is stable and without spikes, it looks like fin rot, which is bacterial.
I suggest salt @ 1tbsp/3 gal and large freq water changes for several weeks keeping the nitrates <5 if possible. Replace the salt to keep the concentration the same w your water changes

I will try that, thanks. Can fin rot effect just one fish in the tank? Everyone else is fine

 

[duanes]

Could be something parasitic.
Are you using live fish as feeders?
These are wild caught tetras infected with Lernaea, its just behind the dorsal fin, adipose and caudal.

I tried using prazi with dubious success, but using Prazi in combination with Metro seemed to work better.

 

[Milingu]

Indeed dubious success. Lernaea are crustaceans. Praziquantel and Metronizol don't work on Crustaceans.

 

[HUKIT]

I agree with danotaylor it does look like fin rot. I generally don’t resort to using any medications for that as clean water and salt is typically enough. I’d start with water changes and salt at two tablespoons per two gallons of water. You’ll start seeing improvements with a 3-5 days but complete regrowth can take up to a month or more.

If you’re not seeing any improvements after 7-10 days then I’d start a couple rounds of Maracyn 2 or Seachem Kanaplex as fin rot is caused by a gram negative bacteria. Poor water conditions is generally the most common cause.

 

[Tpepe321]

Could be something parasitic.
Are you using live fish as feeders?
These are wild caught tetras infected with Lernaea, its just behind the dorsal fin, adipose and caudal.
View attachment 1571357
I tried using prazi with dubious success, but using Prazi in combination with Metro seemed to work better.
View attachment 1571358

No live feeders just shrimp and Hikari / north fin pellets. Haven’t given shrimp in this tank for a while so wasn’t the shrimp either

 

[Tpepe321]

I’m thinking fin rot, the tank had a weird possible crash recently. Odd because the tanks been set up nearly a year without any crashes. Water change schedule was on time etc but did notice a strong smell during a water change a few weeks back did a big change and everything was fine even added a fx6 and will be adding a second recently and removing the 2 110 hobs. I’ll take the existing media from the hobs and use that with the 2nd fx6

For salt fritz says 1 tbsp per 5G, I’m guessing safe to increase because gin rot or stick with the 1tbsp:5g

 

[HUKIT]

I’m thinking fin rot, the tank had a weird possible crash recently. Odd because the tanks been set up nearly a year without any crashes. Water change schedule was on time etc but did notice a strong smell during a water change a few weeks back did a big change and everything was fine even added a fx6 and will be adding a second recently and removing the 2 110 hobs. I’ll take the existing media from the hobs and use that with the 2nd fx6

For salt fritz says 1 tbsp per 5G, I’m guessing safe to increase because gin rot or stick with the 1tbsp:5g

I would do a higher concentration of salt. Depending on what other species you have I’d start with 2tbsp per 2 gallons and possibly slowing increasing that 1tbsp per gallon if needed.