# My son's Betta is very very sick



## Hollythebetta (Mar 5, 2012)

Housing 
What size is your tank? 21L
What temperature is your tank? Varies, but sits around 78-80F
Does your tank have a filter? Yes
Does your tank have an air stone or other type of aeration? No
Is your tank heated? In winter. I am in Australia (QLD) so currently it doesn't need the heater on. 
What tank mates does your betta fish live with? None currently. We introduced a couple of Platys at Christmas but they kept chasing him and nibbling his tail. They are now in a seperate tank next to the Betta. 

Food
What type of food do you feed your betta fish? Started off with Betta pellets, but when we had the Platys in there, he refused to eat the pellets in favour of their flakes. I checked with the pet shop and they said the flakes were fine, so I kept feeding him them even after I took the Platys out. Since he got sick, I've put him back on the pellets. 
How often do you feed your betta fish? Twice a day most days, there is probably one or two days a week where I forget one feed. 

Maintenance 
How often do you perform a water change? I was doing it fortnightly (as I was told by the pet shop) but am doing weekly changes now he's sick. 
What percentage of the water do you change when you perform a water change? I was doing 25% as I was told, last week I did a 75% change and this week I've done a 100% change. 
What type of additives do you add to the water when you perform a water change? Usually just Prime but today I bought some aquarium salt to put in. 

Water Parameters:
Have you tested your water? If so, what are the following 
I took some to the pet shop today and they tested it and said it was fine. 

Symptoms and Treatment
How has your betta fish's appearance changed?
How has your betta fish's behavior changed?
When did you start noticing the symptoms?
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?

I'll answer all this in one go. About 2 weeks ago I noticed that the tank was filthy and Holly the Betta was very very lethargic and staying at the bottom of the tank. He could barely make it up to the top of the tank and wouldnt eat and had some white/colorless patches. I went to the pet shop and they have me a generic "cure-all" to try. I cleaned the tank and gravel etc very very thoroughly in hot water and then refilled the tank to about 75% with fresh water (loads if primer) and the cure all. I let it run for about 5 hours and then put Holly and back in and topped the tank up with the old water. (The pet shop people told me I'd kill him if I did a 100% water change). I removed the carbon cartridge but Im really embarrassed to admit I didn't realise I was meant to change the carbon cartridge in the filter before, so the same cartridge was in for 11 months. 

After the cure-all and switching back to pellets and twice a day feeding instead of once a day, he seemed much better but the white patches were spreading. Holly was doing really well and eating and swimming and seemed really happy but has really crashed again in the last few days. The white/colourless patches are growing rapidly and he's staying at the top if the tank and gulping the air. He's being buffeted around by the filter outlet (that has a new carbon cartridge in it). Ive done a 100% water change today with loads of primer and 1tsp of aquariam salt and he's really not happy still. His tail is either starring to rot or he's biting it, but this is new today. 

Ive taken photos of him to 2 pet shops but no-one can work out what the patches are. They are smooth, not cottony like a fungus. They are practically symmetrical but one side of his body is more pronounced. 

Can anyone tell me what this is and how I can fix him? My son will be devestated if Holly dies....


----------



## Hollythebetta (Mar 5, 2012)

I'll try and work out how to post photos soon. 

Please excuse the spelling and grammar errors - I'm on my phone.


----------



## Tikibirds (May 26, 2011)

I do 100% water changes every week and I have yet to kill a fish. I think for filtered tanks it's 50% every week. Pet store employees tend to be clueless...Anyways...

can you tell us more about the white patches? or a clear pic?

do the white patches look like this or something different?


----------



## Hollythebetta (Mar 5, 2012)

They started off like that, but now they are really big and really white. How do i post a photo like that?

It started around his gills, and now he has big white gills and a saddle-like patch around his dorsal fin. I need to work out how to do photos to show you...


----------



## Hollythebetta (Mar 5, 2012)

http://m.facebook.com/?refsrc=http:...938.1449246805&ref=bookmark&__user=1449246805

Does that work? I'm new to Facebook, so not sure...


----------



## Wolfboy51 (Oct 12, 2011)

it could be ich. But someone else who is more experienced will come along soon.


----------



## Hollythebetta (Mar 5, 2012)

http://m.facebook.com/photo.php?fbi...938.1449246805&ref=bookmark&__user=1449246805

I took this one today. 

I don't think it's ich. From all the pictures I googled of ich, it looks like tiny raised white dots. This is completely different - the patched are white/silver/colourless and large. And spreading.


----------



## Wolfboy51 (Oct 12, 2011)

I cant get the pics working it says their not
Found. Could you try attatching it?


----------



## Hollythebetta (Mar 5, 2012)

OK, let's see if this works....

I took this photo today.


----------



## Hollythebetta (Mar 5, 2012)

Here's some more...


----------



## Hollythebetta (Mar 5, 2012)

He's either a veil tail or a crown tail - I can't remember which, and I don't know the difference between them. The photo where the water is green is because of the cure-all. I did a 100% water change after I took that, but that shows the gill discoloration really well.


----------



## Wolfboy51 (Oct 12, 2011)

Poor guy. I think he is a crowntail, im not too sure on what
The diesease is. But maby it could be a fungus or something. Have you tried taking him to a vet? They may know


----------



## Wolfboy51 (Oct 12, 2011)

It could also be a bacterial or parasite but i think you should take him to a vet. ( if vets treat fish, which im pretty sure
They do) hopefully a vet can help.


----------



## Hollythebetta (Mar 5, 2012)

Hmm, none of the vets around here treat fish. Maybe I should find an aquarium and take him there and see what they say. I won't be able to do that until Thursday though.


----------



## Silverfang (Mar 25, 2011)

For white fuzzies (what it looks like to me in that picture), lower the temp to 75, Warner temps will cause it to grow quickly.

Start with 1tsp/gal AQ salt and increase it to 3tsp/g gradually. Do a complete water change every 12 hours until you teach 3 tsp/gal. After that do daily water changes. A smaller container you cam float in the tank would be ideal.

It looks like fungus, or the dreaded c. I can't post anything more detailed until i get home.


----------



## Hollythebetta (Mar 5, 2012)

It's not fuzzy or furry though. Could it still be fungus?


----------



## Wolfboy51 (Oct 12, 2011)

Maby its advanced fin and tail rot ( it was on the first sticky on this page) or ick, advanced fin rot spreads to the body. And ick has white lumps. Take a look at the first sticky on the diseases page. It may help i really hope he gets better. Good luck.


----------



## Hollythebetta (Mar 5, 2012)

It doesn't look like either advanced fin rot or ich. I have spent days googling and can't find any pictures that look similar (expect the marble ones).


----------



## Silverfang (Mar 25, 2011)

if it's not fuzzy, I'm not sure, try either Sakura8 or Oldfishlady. They have both are great sources of information


----------



## Hollythebetta (Mar 5, 2012)

Ok, so should I be doing 100% water changes daily for now? The pet shop guys said that all the fluoride etc in the water here now meant 100% changes are too stressful for the fish these days. And should I keep him in his big tank or put him in something smaller? I've only got about 75% water in it now and I turned the filter off last night as it is way too strong for him at the moment and he seems much happier this morning. He's still staying up around the top of the tank but he is swimming around. He seems very intrigued by the filter now that it's off. Should i increase the amount of salt in the water today?

Poor little Holly. I'm very attached to him - I never thought fish could be so much fun, but this little guy has real personality and has stolen my heart. He belongs to my eldest son, but all my kids love him. I really want to do the right thing for him....


----------



## inareverie85 (Apr 18, 2008)

Looks like columnaris (also known as cotton-mouth or saddle-back disease) to me.. Sadly, I can't really tell you what to do about treatment, as it is hard to cure, if that is indeed the illness. I hope someone else with more experience in treating it can help.

All I know is that columnaris is a gram-negative highly-contagious (to other fish) bacteria. If caught early enough it can be treated with certain antibiotics, but results are varied. I am not sure which antibiotics though.


----------



## Hollythebetta (Mar 5, 2012)

Thanks for that. I thought it might be that too, due to the saddle-like pattern on his back but there is absolutely no cottony stuff on him anywhere. I haven't found any site that has said a fish can have it without having cottony stuff too, so I'm not sure. 

I just scrubbed the whole tank out, gravel and all and have it running with the filter. Holly is in a 0.5 gal jar with 1/8 tsp aquarium salt (100% water change again) sitting in the larger tank. I have put the heater on low, as the temperature here is fluctuating so I want to see if I can keep it even. 

I stuffed up though and when I changed his water, it wasn't the same temp - it was a fair bit warmer. His gills are flaring and he's breathing heavily but he's active (and cranky). I hope I didn't stress him too much. 

The white patches today are still growing and are shiny, iridescent silver with a blue sheen. Do you think maybe he's just a marble type and the colour change is seperate to the other issues?


----------



## MistersMom (Aug 9, 2011)

orrrrr maybe, he is a marbler.... it may not be a fungus... idk if im the only one who thought this.... but, it looks almost natural... 

i'd still treat for fungus in case tho


----------



## MistersMom (Aug 9, 2011)

its lookes like crackled skin though, the more i look at it.... it may be saddle back.


----------



## Hollythebetta (Mar 5, 2012)

What's crackled skin?


----------



## Olympia (Aug 25, 2011)

It could very well be columnaris.. Either way he is pretty far gone from the looks of it, I'd ditch the aq salt/cure alls and move on to heavier meds at this point. Aq salt is good for the start of an illness, but by now he needs something stronger. I'd message Sakura8 or OldFishLady to look at this thread. You need to know whether to treat for bacteria or fungus. Good luck! Also, he's a crowntail.


----------



## Hollythebetta (Mar 5, 2012)

Thank you. The cure all I used is supposed to treat bacterial and fungal infections, which is why the pet shop girl gave me that one. It didn't help though, the white patches just kept growing (although they are growing faster now I've stopped using it). 

How do I message people?


----------



## Olympia (Aug 25, 2011)

I sent Sakura a message for you
The thing about a general cure all is that it is a weaker medicine that isn't focused on one thing. An acutal fungal or bacterial medicine will be stronger (which is why we use AQ salt for less serious problems) and will be focused on a specific problem, ergo more effective against that problem than just a general medicine.


----------



## Hollythebetta (Mar 5, 2012)

That makes sense. 

Thanks for sending Sakura a message for me. Hopefully she can help!


----------



## Sakura8 (May 12, 2011)

Hi Hollythebetta and welcome to the forum. Olympia asked me to take a look at your guy. Those white patches . . . they're not fuzzy but they're spreading? 

Do you happen to remember where on his body the white patches started? And how was his behavior when they started? Was he doing any darting or rubbing? And you said he has some gill discoloration and he's breathing heavily?

Hmm. I'm pretty certain this isn't a fungal problem. There are only a few true fungal diseases and this doesn't look like one of them. The white spots seem like they could be columnaris but here's where things get complicated: if he has gill or skin flukes, excess mucous production could cause white matte patches on his scales that resemble columnaris patches. That's why it'd be helpful to know if he was doing any darting or rubbing prior.

Don't worry, we'll get to the bottom of this.


----------



## Hollythebetta (Mar 5, 2012)

Sakura8 said:


> Hi Hollythebetta and welcome to the forum. Olympia asked me to take a look at your guy. Those white patches . . . they're not fuzzy but they're spreading?
> 
> Do you happen to remember where on his body the white patches started? And how was his behavior when they started? Was he doing any darting or rubbing? And you said he has some gill discoloration and he's breathing heavily?


Hi Sakura, thanks for your reply. 

The patches are definitely growing and there's new spots coming up. They are definitely not fuzzy at all. The largest one, over his gill, is now shiny with an iridescent blue sheen. His fins under his belly have also turned a brilliant red today. 

The patches started near his gills and around his dorsal fin. They were never fuzzy. The tank was pretty filthy at that point and he was very very lethargic, just sitting at the bottom of the tank and struggling to the surface for air and then going back to the bottom. He stopped eating as well. There was no darting. I did a 75% water change and scrubbed everything out (I even wiped each leaf of his live plant) and let the tank run for about 5 hours with no carbon filter and the cure all before I put Holly and the 25% old water he was in back in the tank. I switched back to feeding him pellets and he cheered right up. I also bought him a new tunnel to hide in which he loves. The patches kept spreading slowly but he was active and happy and eating well. 

The last few days, he has just been sitting right at the top of the tank. He hadn't been as active and wouldn't go down to the bottom of the tank. He was still eating though. The patches are spreading rapidly. 

I've just put him in a 0.5g jar with fresh water with prime and aquarium salt. I've cleaned his tank out again thoroughly and have it running, with the small jar inside it. I had to turn the heater off because on the lowest setting it was creeping up above 83F. I'm in Australia though, so it normally stays pretty warm. 

He's really cranky being in the small jar and is partially flaring at me. He gets really agitated when I get too close and swims up and down and all around and then stops and pants. I took some more photos just now if you want me to post them so you can see how he's going today.


----------



## Sakura8 (May 12, 2011)

Sure, if you want to post the pics, that would be great.

Okay, I musta missed the part about the tank being dirty. That probably means his immune system has been pretty compromised so he could have a few things going on. Right now, the most likely culprit is a bacterial problem because bacterial infections love dirty tanks. Columnaris is a real possibility even though the white spots aren't fuzzy but he could also have mycobacteriosis.

Question: are you allergic to sulfa-based drugs? If you are, then skip to option B right away. If you aren't, then let's try him on API Triple Sulfa, if it's available to you. If you are, then option B is API Furan-2. If neither is available, then Mardel Maracyn II.

Dosing for small volumes of water with these meds can be hard. For this, you'll need two containers, one that can hold at least a gallon and one that can hold at least 5 cups of dechlorinated water. Fill the gallon one up with dechlorinated water. Then fill the other with the 5 cups and add the dosage of medicine (usually 1 packet). Mix well. Now pour 1/2 cup of this water into the gallon you already prepared. Fill his 0.5 gallon jar with this. Change the water every day and redose the medicine for the recommended treatment time (usually 5 days). You probably can keep the medicated water for a day or so but for maximum effectiveness, it helps to mix up a new batch of medicated water every day (using a new packet). Wasteful, I know. The pitfalls of using small tanks. 

I hope this helps you. Good luck and keep us updated.


----------



## Hollythebetta (Mar 5, 2012)

Oh, and when he first got sick and I first got the cure all, is when I realized I should have been changing the carbon cartridge. It went 11 months with the same cartridge. . They didn't tell me I needed to change it and I've never kept fish with a filter before. 

So I'm guessing it could have started off as amonnia burns or something?


----------



## Sakura8 (May 12, 2011)

(AAARGH, lost all that I typed!!!!!)

Starting over. To be honest, you don't need carbon. It doesn't really do anything except keep the water clear and you have to replace it every other week for it do that much. However, in your case, because you didn't change it for almost a year, you built up a lot of good bacteria in it because carbon IS good for cultivating good bacteria since it's really porous. When you finally changed the carbon, you threw away all that good bacteria and your tank probably crashed because of it. It happens, we've all had our tanks crash for one reason or another. So yeah, ammonia poisoning is probably a factor in Holly's illness.

What kind of filter is it? In all actuality, you don't need to change the filter cartridges unless they get so filthy they don't work anymore. When you change them, you lose all the good bacteria. All you really need to do is remove the cartridge and rinse it in old tank water (never new because chlorine and heavy metals in raw tap water kills the bacteria) and replace.


----------



## Hollythebetta (Mar 5, 2012)

Sorry, I didn't see your reply when i posted that. I will go to the pet shop this evening and see what I can get. I'm not allergic to sulphur-based medications but my baby who is still breastfeeding is. Should I still go straight to option B?

I can put him back into the larger tank and change that daily if it would be better for him...


----------



## Hollythebetta (Mar 5, 2012)

Ok, I didn't see that reply either!

It's just a standard waterfall filter. I actually bought a 2 goldfish set-up but bought a Betta instead. 

He was sick before I changed the filter and I'm sure the white patches were starting before I changed it too. I kind of regret changing it now! 

I'm wondering now if I've just stressed him majorly with all these water changes when he's used to old water with loads of bacteria and now I keep stripping it back.

Oh, and your profile picture reminds me that one of my cats loves to drink the water as it comes out of the filter. Could that influence anything?


----------



## Sakura8 (May 12, 2011)

Hmm. If your baby is allergic, let's not risk it. If you can find Furan-2, that would work fine. 

It's possible the initial water changes did stress him but once he gets used to a routine, he'll be much better. Maybe 40-50% a week would be good, if you can do that. 

Having a cat drink out of the filter shouldn't do any harm to either fish or cat. Cats love running water. Haha, since my tank didn't have a filter my cat decided it was a perfect window perch instead.

Oh yeah. If you think Holly would be happier in his tank and you don't mind doing 100% water changes on it, then you can certainly put him back in.


----------



## Tikibirds (May 26, 2011)

How is he doing?


----------



## Hollythebetta (Mar 5, 2012)

I think he's actually doing ok. I didn't get to the petshop in time today (they closed earlier than I thought) but he seems ok. He's still in the little jar and quite annoyed at me for it, but he's resting on the bottom and will swim up to the top when he sees me. The white patches are still there, but looking more silvery/pale blue and are shiny and iridescent now. I'm really starting to wonder if he is just a marbler but got sick from the dirty tank and the two things are unrelated. Or maybe the stress of the dirty tank caused him to start changing colour. Whatever the reason, he seems to like the salt. 

Oh and yes, I know it's an interesting name for a boy. I tried to explain to my son that Ollie was the boys version but he insisted on Holly. I don't know if you've ever tried arguing with a 5yo who has made up his mind, but it's damn near impossible.


----------



## Wolfboy51 (Oct 12, 2011)

Lol ive tried and failed. 6yo cousin.
Good to hear hes doing well.


----------



## Hollythebetta (Mar 5, 2012)

I've just given Holly his dinner and he seemed really happy. He blew a few bubbles at me after he finished. 

BUT the gill that has turned white/silver seems like its sticking out slightly. The other gill goes in flat when he breathes but the discoloured one stays flared out at the bottom. Does this help with working out what's wrong with him? I think maybe I was wrong about him being a marbler...


----------



## Olympia (Aug 25, 2011)

Marble Berra start white and turn darker, I never heard it being the other way around


----------



## Hollythebetta (Mar 5, 2012)

Oh really? I read somewhere that they can start darker and turn white. I can't remember where though, I have been googling for days trying to find something that matches what Holly has. But it had photos....


----------



## Hollythebetta (Mar 5, 2012)

http://bettysplendens.com/articles/page.imp?articleid=1114

This is one of the articles I read on the weekend...


----------



## Tikibirds (May 26, 2011)

> The Jumping Gene continues to eliminate the colored cells until the betta has a flesh colored body. It continues to affect the fins by reducing the expression of the turquoise and replacing it with white or clear. The red "wash" that was always present in this fish from the beginning now stands out more noticably, creating a very nice, contrasty, colorful tricolor marble!


Wow....he went from blue to butterfly red :shock:

Supposedly there is also something called a color loss gene but I have no idea what that is. 



> I tried to explain to my son that Ollie was the boys version but he insisted on Holly. I don't know if you've ever tried arguing with a 5yo who has made up his mind, but it's damn near impossible.


It's OK. I have a MALE dog I named Bubbles :-?. He was SUPPOSED to be a female....


----------



## BETTACHKALOVE (Nov 22, 2010)

hello i tried to read all thread ... maybe i missed something...sorry if i will repeat that someone already said. Holly you still adding aq salt not medications right?
Do you do 1tsp/gall ? I thought that i read you do 1/8 for 0.5 gall. The right dose 1tsp/gall which is 0.5 for 0.5 gall with daily 100% water changes. And you don't use it longer than 10 days. And it better pre mix it in 1 gall jug. 

Also one time you wrote that you change the water and the water was warmer then he was in. Since you weater is warm and you don't need heater you can let the water sit over for 4,12 or 24 hrs. This way the water will be the same temp .


----------



## Hollythebetta (Mar 5, 2012)

I know tikibirds! I still find it hard to believe its the same fish!

BETTACHKALOVE - I forgot to say that he started off in 1/8tsp salt and I was going to increase it over a few hours (which I did up to 1/2tsp). That's such good thinking about letting the water sit for a few hours before I change it so it's the same temp as Holly. Can't believe I didn't think of it.


----------



## Olympia (Aug 25, 2011)

That fish is crazy. You learn something new every day! I read about a breeder who was determined to keep red out of most of his strains, because it is a very dominant gene. It's crazy that they chance so much. Makes me want to buy a ton of marbles lol. Yet paired with the fin conditions and the situation be was in, it'd be a coincidence that he's randomly marbling now. However that fact that he's active is really good.


----------



## Hollythebetta (Mar 5, 2012)

OK, Holly is still nice and active today and eating well. I've done a 100% water change with 1/2tsp salt (1/2gal jar).

BUT we have some changes. The white band that was giving the saddle mark on his back has moved down and is closer to his belly now. I also noticed a tiny white dot at the front of his dorsal fin yesterday, where it joins his body. Today it's spread quite dramatically and he has a few holes in the fin. Is this fin rot or is it the same thing? I also noticed today that his long fins under his belly (there's two - one on each side) each have a white spot on the end and one is shorter than the other. Again, is this fon rot?

The patches on his gills are definitely shiny silver with a blue sheen now. I think there's less white on him overall today.

I've taken some more photos and I'd really appreciate your thoughts!


----------



## Tikibirds (May 26, 2011)

So the white is deffidently not fuzzy or raised off his scales in any way, right? it does not look like the scales are beining eatten away, like here:










Is he acting normally?


Im thinking, and and I can be totally wrong, but if his water was really bad, maybe he his gill was burned by ammonia and thats why it wont close? I think there is also something called gill disease but i'm not sure what that entails...


----------



## Hollythebetta (Mar 5, 2012)

Definitely not fuzzy or being eaten away, but it is slightly raised on the bad gill. Almost like it's an extra layer of scales over the top. 

I wouldn't be surprised if was ammonia burns or something that started it, but would it still be continuing now that he's been in clean water for so long?


----------



## Tikibirds (May 26, 2011)

> but it is slightly raised on the bad gill. Almost like it's an extra layer of scales over the top.


I am no expert but i'm thinking if it was an ammonia burn, the extra layer may be like scar tissue healing over the burn? I'm not sure how long it takes to heal. Fins grow back rather quickly if water is kept clean and warm and stress coat helps.


----------



## Sakura8 (May 12, 2011)

I second Tiki on the scar tissue from ammonia burns on the gills. But the white patches are still something of a mystery to me. Depending on the severity of the burns, the gill may or may not ever be able to close properly. When it can't close properly and sticks out because of scar tissue or gill flukes, it's called gill hyperplasia. This is sometimes permanent but usually doesn't affect the quality of life too much as long as the water is kept clean.

Have you started any medications? If not . . . well, I think I'd actually like to try him in AQ salt for another week before hauling out meds. If you have, don't worry about it.


----------



## Hollythebetta (Mar 5, 2012)

I think he's getting better. There's definitely less white/silver on him today than there was a few days ago. I am concerned about his dorsal fin though and I do think he has fin rot. Will the AQ salt treat this or does he need something else? I haven't been able to get the antibiotics for him yet, do still just doing salt and daily 100% water changes in the jar but I can get whatever I need today.


----------



## Sakura8 (May 12, 2011)

The salt should help ward off any fin rot. I would definitely keep him in the salt for another week or at least until the spots are almost gone. If you can, you can pick up API Stress Coat. That will also really help with the fin rot issue. 

I'm glad to hear he's doing much better. yay!


----------



## Hollythebetta (Mar 5, 2012)

Thanks Sakura! I will definitely get some stress coat today and start using that. My husband thinks I'm nuts for going to so much effort and expense for a fish, but I'm really attached to this little guy. I'm so happy he seems to be improving. I think Holly means more to me than to my son!


----------



## Olympia (Aug 25, 2011)

That usually is how it starts with the love of betta


----------



## Hollythebetta (Mar 5, 2012)

I"m bumping this up to the front page again. I've started a new thread - Holly's dorsal fin is deteriorating and he's expelling bubbles from his mouth and gills.  I think it may be time to euthanise him, but want confirmation first. 

Just out of interest, the silver/white is nearly all gone now and he's regaining his colour, but darker and not as vibrant. This is what he looks like today:


----------



## Olympia (Aug 25, 2011)

Oh, that poor thing.
How is he acting? He's pretty skinny, how's his appetite? He looks pretty horrid, but if he's acting better I think you should give him some more time before putting him down.


----------



## Hollythebetta (Mar 5, 2012)

He's eating, but when he eats, air bubbles come out of his gills. He seems panicky and not happy. He's getting skinnier and skinnier despite eating well. He's obviously suffering today and I think he's quite scared and exhausted. As much as it breaks my heart, I think I need to end his suffering. :sob:


----------



## Olympia (Aug 25, 2011)

Hmm. Maybe he has internal parasites? You could treat for that..
It is your call.. If someone more knowledgeable agrees with you then I guess it'd be time.
The most humane way to do this would be to prepare an icy cold tub of water, like frothy, near frozen. And just plop him into that. This will put him in immediate shock and he will die pretty quickly.
And I'm sure you know this but thoroughly clean everything that was in his tank and his tank before adding any other fish...


----------

