Who Gives A Fish Forums

My betta's fins are looking ragged and he's been lethargic for days. Water params are good, 0 ammonia, 0 nitrite, 5 nitrate. He's in a 5 gallon with a sponge filter, heated to 78F. Could this be a bacterial infection? What's the best treatment?

Sounds like fin rot, which is usually bacterial. I'd start with daily 25% water changes and add aquarium salt at 1 tsp per gallon. If it doesn't improve in a week, try an antibiotic like erythromycin. Keep the water super clean, that's key.

Yeah, my dude had the same thing last month. I used API fin and body cure, worked like a charm. Just make sure you remove any carbon from the filter first, or it'll suck up the meds.

rizonix wrote: ↑Thu Jul 31, 2025 10:16 am Sounds like fin rot, which is usually bacterial. I'd start with daily 25% water changes and add aquarium salt at 1 tsp per gallon. If it doesn't improve in a week, try an antibiotic like erythromycin. Keep the water super clean, that's key.

Agreed, but be careful with salt if you've got live plants. Some can't handle it. Also, bump the temp to 80F to boost their immune system.

I've heard mixed things about salt. Is it really necessary for mild cases? Couldn't just clean water and meds cut it?

Salt's a good first step 'cause it's gentle. But if your fish is really struggling, meds are the way to go. I've had success with Kanaplex, but it's strong stuff. Only use it if the salt doesn't help.

Flynest wrote: ↑Thu Jul 31, 2025 2:03 pm Salt's a good first step 'cause it's gentle. But if your fish is really struggling, meds are the way to go. I've had success with Kanaplex, but it's strong stuff. Only use it if the salt doesn't help.

Kanaplex is solid, but it's overkill for early fin rot. Stick to erythromycin or Maracyn first. Save the heavy hitters for when things get sketchy.

Thanks for the advice, everyone. I'll start with salt and water changes, then move to meds if needed. Appreciate the help!

Keep us posted on how he's doing. Sometimes it takes a bit to see improvement, so don't get discouraged if it's slow.

Yeah, patience is key. My guy took two weeks to fully bounce back, but now he's flaring at everything like nothing happened.