Originally Posted by DoctorWhoLuver
He looks like a she to me, unless he's a king betta. How long is he?
Also, what exactly are his symptoms? From what I got, it was lethargy and trouble swimming? Did you check for velvet or the color of his poo yet? Is he flashing? You mentioned that he was " turning" when swimming, that sounds like SBD. It's hard to see his caudal fin, but from what I can see, there doesn't seem to be fin rot, only a slight clamping. Do you have anymore pictures of his caudal fin? His dorsal fin looks like it was bitten.
You will need a heater anyway, bettas are tropical fish. It will help reduce stress and SBD if he does have it.
Water changes are very stressful, no more than one a day.
The ammonia will get too high too soon if he only has one a day, there's only .5g of water in there right now so he can reach the surface.
And he wouldn't stay still for the pictures, but what you see in the first photo, that's the whole fin. That's it. If he/she was in a tank with other fish before his cup, I don't know. But she got him in a cup at the pet store, and when I asked about his fin, she said it always looked like that.
He doesnt have velvet symptoms I don't think.... and his poo seems normal, the small bit that was in the bowl before I moved him to his new setup.
I know he's tropical, but he's within the range set for bettas.
Length, he's/she's...between 1.5-2 inches.
Exact symptoms were lethargy, but he has bursts of energy (not darting, but actual swimming around) between rests now that he's in clean water. At least I think that would be why. His fin looks damaged, and has black along the top edge.
As for flashing..not sure what you mean? As in colors or stripes? Cuz he's striped a bit still, but he did arrive dark, and now has more red in his fins.