I work at a local pet store near my home and we recently noticed a rescue betta we've had for a couple months acting oddly. I volunteered to bring him home and currently have him in a quarantine tank but I'm afraid he's not looking too good. Any help would be appreciated.
Back story: the tank he has been housed in since surrendered is a 30gallon with several different species of fish and plants that come and go as they are sold. All the parameters are excellent except for some moderate water hardness, but that comes from our local tap and has not changed ever. this tank is a well established tank, several years old never with any problems. Only fish to ever die were ones which came to us injured.
So Bixby as I have taken to calling him has been with us for about 2 months now. He was surrendered healthy and happy, no issues. We noticed about a week ago he began to get rather lethargic and lazy. Rather rapidly however over the last three days he has gotten quite worse. the parameters in the store tank are fine and have not had any issues, nor have any of his tank mates. I brought him home and put him in a half full 10gal (about 5 - 6 gallons full so he can reach the surface easier).
Currently his parameters are:
pH about 7
and moderate water hardness
his tank is staying around 76 - 78 degrees F and I currently have not put my extra filter in with him. (I'm using it as a supplemental filter for another tank and do not want to contaminate it in case he does have a disease i cannot treat). In the mean time I am keeping an eye on the water and changing out small parts (10%) once a day. I did add 1/2 teaspoon aquarium salt (fully dissolved) to the tank before adding him. the store tanks have very minimal quantities of salt in the water (to deter pest snails and for precaution against diseases) so I don't think it is causing him any distress. He has never had any problems before recently.
-He is extremely lethargic, only moving when he needs to surface (which is becoming increasingly often (only slightly rapid breathing)).
-his eyes seem slightly distended and milky, and he seems to be bumping into the two pieces of decor i put in with him to give him hiding places to keep stress down.
-his fins have been about half clamped, not fully flared but not tight against his body either.
-when he does swim, he darts about like a healthy betta but quickly sinks back to the bottom when still.
-this morning he was laying on his side/flat on the bottom of the tank, but now he's taken to facing straight up at the surface like a rocket. all other symptoms are the same.
I know more often than not when fish act sick they're on the way out, but this guy seems fairly young and I want to see if there is anything I can do. He's eating small amounts of freeze dried bloodworms and a couple betta floating pellets, but he's absolutely refusing deshelled peas (broken up) or any sort of flakes.