Betta Fish Care  
Go Back   Betta Fish and Betta Fish Care > Betta Fish Diseases and Emergencies
Check out the eBook Betta Fish Care Made Easy
betta fish
Thread Tools Search this Thread
Old 08-05-2011, 03:30 AM   #1 
New Member
Join Date: Aug 2011
Need help diagnosing fin rot/secondary fungus infection!

Hello everyone and thank you for taking the time to read this post.

My name's Karsten and I am posting on behalf of my girlfriend's betta, Fish. He's very ill. Here's the copy/paste.

What size is your tank? 3.5gal
What temperature is your tank? Room temp ~72-80F
Does your tank have a filter? Yes (We're not using it now.)
Does your tank have an air stone or other type of aeration? No
Is your tank heated? No
What tank mates does your betta fish live with? Bachelor pad

What type of food do you feed your betta fish? Hikari Betta Bio-Gold
How often do you feed your betta fish? Once per day


How often do you perform a water change? 3.5gal tank, twice weekly 33% but used to be in .5 gal tank with once weekly 100% changes. Let me apologize now, we were both irresponsible betta owners.

What type of additives do you add to the water when you perform a water change? Water conditioner

Water Parameters:
Have you tested your water? If so, what are the following parameters?


Symptoms and Treatment
How has your betta fish's appearance changed? Fish's dorsal fin has rotted off, seemingly revealing two dorsal fin bones. White fuzzy material seems to be infecting this area. Additionally white patches seem to be eating away at the tips of some of his other fins and even eating a hole in the middle of the fin. One patch we are particularly worried about is at the base of his butt and seems to be threatening to remove his rear fin and strike at the body.

How has your betta fish's behavior changed? His behavior hasn't changed much. He's a really fiesty fish and still energetic and vigorous, regardless of his lack of a dorsal fin. He eats voraciously and completes all his meals. I've been feeding him a little extra, trying to supply him with some extra building materials to rebuild his fins and fight the microbes.

When did you start noticing the symptoms? The tail patches seem to have been there for quite some time, not sure if he had them when we got him from the pet store. Dorsal fin detached three weeks ago, girlfriend tells me.

Have you started treating your fish? If so, how? After noticing his issues, I began flexing google muscles. We upgraded his tank. Then we started using bettafix. Naturally, this was at the suggestion of the pet store employee, who I doubt truly cared. We used bettafix for about two weeks with no noticeable change. I was worried that he was getting worse, so we picked up some E. erythomyocin by API. Unprepared, again, I find now that this medicine is not effective for gram-negative fin rot. We've done the initial two doses of erythromycin.

Does your fish have any history of being ill? Uh, possibly. We've let whatever he has now go on too long.

How old is your fish (approximately)? Fish just celebrated his third birthday on the 31st of July.

I'm attaching some pictures that will hopefully illustrate what's going on here. I'm finished blindly buying medicines to try and help poor fish and will turn this diagnosis over the the experts. Please help us! We're both committed to giving him a healthy, comfortable life.

karstenchu is offline   Reply With Quote
Old 08-05-2011, 03:36 AM   #2 
Abby's Avatar
Join Date: Jan 2011
Location: Lismore, NSW
OH my goodness! i dont know but the poor boy!
Abby is offline   Reply With Quote
Old 08-05-2011, 04:46 AM   #3 
New Member
Join Date: Jul 2011
Location: Florida
That looks like advanced fin rot and I think I see some on his tail, too. Bettafix, I'm coming to find out with my own betta, does little to nothing. Adding aquarium salt can help a lot. Read the sticky if you haven't already.
Mindibun is offline   Reply With Quote
Old 08-05-2011, 08:10 AM   #4 
Join Date: May 2011
Location: Elk Grove, California
Hi karstenchu and welcome to the forum. No need to apologize about anything, you are more than making up for it by seeking help. It's the people who refuse to change their habits that drive us nuts here. People like you and your girlfriend who genuinely want to learn how to care for their fish are most welcome.

First, yup, that looks like a nasty case of finrot brought on by poor water quality. Maracyn-II is the medicine you'll want. It's effective for gram-negative bacteria. If you don't have him in a small QT container, you'll want to get one ready because keeping him in something small, like his old .5 gallon tank if you have it still, will make this easier because you need to do daily water changes.

The best way to treat with Maracyn-II is to get a big jug and mix 5 cups of dechlorinated water with the recommended dosage of Maracyn-II. Shake it well, then use 1/2 cup of this mixture per gallon of his QT container (so, uh, if he's in his .5g tank, whatever half of half a cup is; sorry, I really stink at math). Save the rest of the mixture, you'll need it. For the duration of his treatment, do daily water changes and redose the medicine. The premixed meds should be good for about two days, then you'll need to mix more up. Also try and keep him as warm as possible. Unless you live in a tropical area where the ambient temp never drops below 80 degrees, you'll want to pick up a heater. If you can get the temp of his container up to about 84 degrees, that would be great. Also, Maracyn-II can be a little light sensitive so keeping his tank dim will help him.

He's a very handsome fellow. I should mention that his age may play a part in his ability to fight off this infection. 3 years old is very old for a betta; their average lifespan is about 1-3 years so your guy is a senior citizen. Since he's still eating, I have great hope he'll shake it off. One thing you can do to help is feed him a high protein diet. If you can, get frozen bloodworms and feed those to him. Break his meals up into at least two a day and feed him a few small bloodworms for one meal and 1-2 pellets for his other.

I hope this helps your guy perk up. Keep us posted.
Sakura8 is offline   Reply With Quote
Old 08-05-2011, 05:56 PM   #5 
New Member
Join Date: Aug 2011
Thanks for the advice! Is there a way to tell if he needs a medication to treat gram negative or gram positive bacteria? Also should we do the whole treatment with the medication we have now and then try the Maracyn-II. Is it dangerous to switch meds on him all of a sudden?
karstenchu is offline   Reply With Quote
Old 08-05-2011, 09:33 PM   #6 
Join Date: May 2011
Location: Elk Grove, California
There isn't any real way to tell if most bacterial infections (especially internal infections) are gram negative or gram positive without a test. However, fin rot is most definitely caused by a gram negative rod bacteria, aeromonas or pseudaeromonas.

Are you still treating him with erythromycin or is it the Bettafix? If it's Bettafix, I recommend stopping immediately, as it contains an ingredient - tea tree oil - that could harm the labyrinth organ of a betta. If you want, you can put him in clean water for a night to give him a break from the medicine, then start the Maracyn-II. It shouldn't hurt him to switch suddenly, but it never hurts to be careful.
Sakura8 is offline   Reply With Quote
Old 08-10-2011, 05:08 PM   #7 
New Member
Join Date: Aug 2011
We decided to keep treating him for a full 10 days with the erythromycin. So far it has been 6 days. We also added some aquarium salt as that was also suggested to us. His water has been a good temperature 79-80 F. He is still swimming well, still eating and greeting us whenever we approach his tank and is very vigorous. He now has some white on his dorsal fin on the side opposite to the camera it doesn't look cottony it looks more like his blue area near there is turning white. On another forum it said that white is a sign of healing so it is good. If after the 10 days pass and he still isn't really looking any better then we will switch to Maracyn 2. Here is a picture of him from a few minutes ago what do you guys think?

karstenchu is offline   Reply With Quote
Old 08-10-2011, 08:37 PM   #8 
Silverfang's Avatar
Join Date: Mar 2011
Location: Newfoundland
I know that new growth of fins starts as a clearish/white. Hopefully that is what you are seeing.
Silverfang is offline   Reply With Quote
Old 08-11-2011, 12:19 AM   #9 
Join Date: May 2011
Location: Elk Grove, California
It's a little hard to tell. New growth is usually nearly transparent but with a whitish look to it, if that helps. Hopefully it is new growth. If it isn't cottony that is a good sign.
Sakura8 is offline   Reply With Quote
Old 08-15-2011, 01:21 AM   #10 
New Member
Join Date: Aug 2011
So after continuing treatment with erythromycin, his dorsal is looking like this...I honestly can't tell what is going on, whether the rot is continuing, whether the white is a fungus (it doesn't look cottony or like hair, but has a solid look to it), or whether that white stuff is a scab material and it's healing over.

Fish is still quite energetic in his hospital tank. He keeps eating whenever he is fed and some overfeedings have led to some very large poo. That's my boy!

Just kidding, we're feeding him normally now. Our food, we discovered, has expired many months ago. Does Hikari Bio-Gold truly go bad? Could expired food be the cause? We're probably going to pick up some new stuff tomorrow.

Behold Fish in his beautiful glory. In this first one you can see some of his fin bones protruding. They don't seem to be as visible as they were before, however.

Here is another picture of the other side of the dorsal. You can see red here now.

We're thinking about continuing erythromycin (Maracyn) and beginning Maracyn II, using both concurrently. The boxes for the Maracyn II claims that it can be used safely with the other, so I feel like it's worth a shot. Poor fish!

Besides this, we are doing daily full water changes with aquarium salts and conditioners. His temperature is right and we would check other parameters but we can't afford the stupid tests. Any additional advice would be highly appreciated.

Last edited by karstenchu; 08-15-2011 at 01:24 AM.
karstenchu is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
need help diagnosing sick betta lex72 Betta Fish Diseases and Emergencies 14 08-06-2011 10:11 AM
Need help diagnosing this fish. vamprus Betta Fish Diseases and Emergencies 3 06-29-2011 05:22 PM
Jungle Fungus Clear? My betta has a serious fungus problem... BlueHaven Betta Fish Diseases and Emergencies 16 05-21-2011 03:26 PM
Help diagnosing sick Betta bettacanada Betta Fish Diseases and Emergencies 7 10-13-2010 09:45 PM

All times are GMT -5. The time now is 10:10 AM.

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.