I've just noticed he has a greyish mark across the top of his tail, I'm wondering if this has anything to do with it... Will have a read of threads etc.
My first thought was swim bladder, but he is still upright all the time.
To me, he acts normal, happy etc, then just seems to get tired and sink to the bottom, only to swim upwards again to surface..
Your size tank (which equals to approx 1.3g) is just fine - male bettas don't need that big of a tank, as these long finned are domesticated and not short finned as their wild counterparts are - their territories don't need to be 3ft squared. A 1 gallon is a suitable home for a male betta and there is plenty of room for him to move around in. In fact, a lot of the bigger finned bettas would benefit more from the smaller tanks.
Water can be too clean - why it's recommended 1 50% and 1 100% weekly to give them a good balance of clean water and the bacteria they need for their immune system. Make sure to use full dose of water conditioner when doing the 50%s.
As far as why he is lethargic.. it's hard to say. I would look into all the possibilities such as a bad water conditioner if you just got it (or if it's pretty old), him or a neighboring tank being moved away, low quality food.. it's not the temp, as that is just fine and wouldn't cause lethargy to this extent.. it takes a lot colder water to cause it.
Possibly something got into his water at some point and is causing him to act this way.. but he is still eating which is a good sign.
When he swims to the surface, does it look like he is having any difficulty? Struggling to stay up once there?
Wish I could be more help, but there isn't any obvious signs in your care that would cause this, nor any other symptom other than his lethargy.. if he is having troubles swimming, I would recommend Epsom Salt - as that is the only thing I feel comfortable giving advice on to help him that would be safe for him right now since we don't know exactly what is going on.
Epsom Salt - found in most pharmacies (human section), dye/fragrance free -
2tsp per gallon with water conditioner (make sure to dissolve it first before placing him in it - hot water helps to dissolve the salts faster, will need to stir continuously), daily 100% water changes adding in the salt/conditioner each time.. could take a week or more to resolve any issues if it has anything to do with his swim bladder (which keeps them upright and swimming normal).
Thank you myates, you've given me some very helpful information
I have just purchased some epsom and melafix... Do you think that may help with the fin repair?
In answer to your question, once he rises to the surface, he can't hold himself up there, flaps like crazy for a few seconds, and then just sinks... Like he's over done it or something. The only way he holds himself at the surface is if he sits ontop of his thermometer...
His food hasn't changed, water conditioner is the same brand I always use and its still fresh.... :-S
Don't use Melafix. It can damage their labrynth organ and kill them.
It's hard to tell from your photo, but there may be some fungus on the fins.. If you don't want to try a real medication you can try the epsom salt as suggested. It has anti fungal properties and could help if he's got something going on with the swim bladder.
What does the poop look like? Do you feed 5 a day or 5 twice a day? Do you fast once a week?
Keeping bettas healthy in 1 gallons is really difficult and never ideal. You have to be extremely diligent in keeping up with water changes, you have to find a way to heat the bowl properly (either live in a hot climate or dedicate a room to the fish that you can climate control separately), and you have to be really really aware of water chemistry and any potential swings. I've done it. I don't recommend it. I don't think my bettas are ever as happy or healthy and they're not going to live the 6, 7 and 8 years that they potentially can. With something that small they are going to see weekly traces of ammonia, and even small traces of ammonia eventually will wear a fish down. Usually they make it 1-2 years in the bowl. Sometimes 3 and 4. I've never seen more.
When you say real medication, what exactly do you mean?
whilst I appreciate the feedback on tank size, I am very much aware of the upkeep that is required. This is not my first betta, and certainly not my first tank. His neighbour is 5 years old, and he has lived in his 5.5 lt for the entire time.
Heating is no problem, as previously mentioned the temperature is stable, as is the ammonia levels, I test all my 1-2 times per week, and have never experienced an ammonia spike in any of my betta tanks.
As for any deseases, I have no signs at all, except for a tiny grey bit on the upper of his tail.. hence why I'm so confused as to what the problem could be
Real medication= not salt. Melafix would fall under that category. However, anything with 'fix' in it (metafix, bettafix, etc..) has an ingredient in it that damages the labyrinth organ.
May I ask how long the grey on his tail has been there?
Yes, I understand real medication not being salt, I thought i was being referred to a medication that worked lol.
I have read about the problems with betta fix, hence why I was asking as I had some melafix from a previous purchase with another tank.
The grey spot has been there probly 3-4 days now. When I say grey, its a lightened colour of what he is now, he's cobalt blue, with a hint of green, purple and red on his outa fins.
How do I work out if its fin rot? There are no obvious signs or stringy white or anything?
Oops... And previous question, his poop is orangey/brown ish, and he feeds 4-5 pellets twice a day, and I haven't fasted him.
I don't know if you have read the thread about the mystery disease that causes strange gray discoloration in the fins or not. It generally affects blue bettas. Your betta doesn't have it, but it is useful information to have. It spreads rapidly, so that's why I asked how long the grey spot has been there.
For fin rot..
•Symptoms: Betta’s fins and/or tail seem to be getting shorter and shorter or they seem to be falling apart and dissolving, Black or red along the edge of the betta’s fins/tail, Bloody tips, Behavior may not change.
Quoted from Betta Fish Disease and Treatment part 1 (sticky).
Have you read both of those posts? Lethargy is a common symptom of many things, including stress. The only other thing I saw that had anything to do with grey spots was Columnaris, but it is described as a lesion, so I'm not so sure about that one.