Yeah he's dashing along the corners of the tank and twitching.. I don't really know how to describe the twitch it's just like a sudden twitch in the base of his torso. He was sort of monotonously swimming along the edges of the tank and bumping into the corners as he did it.
Twitching Betta..
I just got home and my Betta is acting really strange.. A little backstory: I have 2 Bettas that used to be in a divided 5.5 gal tank. They were like that for about 3 months. They were happy as could be until I got a new divider which was see-trough and both of my fish started biting their fins so I assumed they were stressed by each others presence. Because of this I gave them both their own 5 gal tanks. I did the whole change over yesterday. My HM Betta is the one which is worrying me currently. He is always very energetic and happy to see me and eager to eat. I just got home and he hardly ate any of his food and is hovering at the top of the water.. It's not extremely noticeable but it's very unlike him to act like that. He's being lethargic and worst of all, he's twitching! I've never seen or heard anything like this but I'm terrified 
when I changed his water to use his new tank I did a 100% water change and used stress coat as the water conditioner. I used the double dose to clear up his fin issues like it says on the bottle. I also added 1 tbsp of aquarium salt... Nothing major? Help please I'm so worried..
Housing
What size is your tank? 5 gal
What temperature is your tank? 82
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? No
Is your tank heated? Yeah
What tank mates does your betta fish live with? None
Food
What type of food do you feed your betta fish? Omega one Betta buffet pellets
How often do you feed your betta fish?3 pellets 2 times a day
Maintenance
How often do you perform a water change? Haven't yet
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change?
Water Parameters:
Have you tested your water? If so, what are the following parameters?
Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:
Symptoms and Treatment
How has your betta fish's appearance changed? He is a marble Betta so it's hard to tell. Recently he turned back to his pink color but before today he was fine.
How has your betta fish's behavior changed? He keeps twitching, being lethargic, not eating as much, and staying near the top of the tank
When did you start noticing the symptoms? 5 mins ago
Have you started treating your fish? If so, how? No
Does your fish have any history of being ill?
How old is your fish (approximately)?
when I changed his water to use his new tank I did a 100% water change and used stress coat as the water conditioner. I used the double dose to clear up his fin issues like it says on the bottle. I also added 1 tbsp of aquarium salt... Nothing major? Help please I'm so worried..Housing
What size is your tank? 5 gal
What temperature is your tank? 82
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? No
Is your tank heated? Yeah
What tank mates does your betta fish live with? None
Food
What type of food do you feed your betta fish? Omega one Betta buffet pellets
How often do you feed your betta fish?3 pellets 2 times a day
Maintenance
How often do you perform a water change? Haven't yet
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change?
Water Parameters:
Have you tested your water? If so, what are the following parameters?
Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:
Symptoms and Treatment
How has your betta fish's appearance changed? He is a marble Betta so it's hard to tell. Recently he turned back to his pink color but before today he was fine.
How has your betta fish's behavior changed? He keeps twitching, being lethargic, not eating as much, and staying near the top of the tank
When did you start noticing the symptoms? 5 mins ago
Have you started treating your fish? If so, how? No
Does your fish have any history of being ill?
How old is your fish (approximately)?
