Please help me i dont want to see this little guy sad!

 

He may have. Try testing the water and checking the temp. He may be stressed out.

 

try to fill this out:


Housing
What size is your tank?
What temperature is your tank?
Does your tank have a filter?
Does your tank have an air stone or other type of aeration?
Is your tank heated?
What tank mates does your betta fish live with?

Food
What type of food do you feed your betta fish?
How often do you feed your betta fish?

Maintenance
How often do you perform a water change?
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?
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)?

he maybe has a swim bladder problem...

 

Housing
What size is your tank?10gal
What temperature is your tank?not sure
Does your tank have a filter?yes
Does your tank have an air stone or other type of aeration?freshwater plants
Is your tank heated?no
What tank mates does your betta fish live with?none he killed them

Food
What type of food do you feed your betta fish?betta pelets..7 a day
How often do you feed your betta fish?once a day

Maintenance
How often do you perform a water change?every 2 weeks
What percentage of the water do you change when you perform a water change?100%
What type of additives do you add to the water when you perform a water change?water conditioner

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?no
How has your betta fish's behavior changed?yes he has one fin now that wont stop moving rapidly...and a month ago he started sitting at the top of his tank
When did you start noticing the symptoms?two hrs ago
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?6 months

 

Bettas are also known as Siamese Fighting Fish, so yes, they are aggressive enough to have killed your tetras. He does not seem tank-mate compatible, lol. Also, tetras should always be in groups of at least 5 (for future reference).

Housing
What size is your tank?10gal
What temperature is your tank?not sure
You probably need a heater and a thermometer. Make sure the water temp is 76-82.
Does your tank have a filter?yes
Does your tank have an air stone or other type of aeration?freshwater plants
Is your tank heated?no
What tank mates does your betta fish live with?none he killed them
I recommend this betta be a solo-betta.

Food
What type of food do you feed your betta fish?betta pelets..7 a day
This is a lot for one meal, I would feed about 2-3 pellets a day, twice a day. No more. Make sure to split the meal so his tummy isn't stuffed and overwhelmed.
How often do you feed your betta fish?once a day

Maintenance
How often do you perform a water change?every 2 weeks
What percentage of the water do you change when you perform a water change?100%
You should always do at least 50% every single week, probably more for you since your tank isn't cycled. (doing the 100% changes will kill it).
What type of additives do you add to the water when you perform a water change?water conditioner

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?no
How has your betta fish's behavior changed?yes he has one fin now that wont stop moving rapidly...and a month ago he started sitting at the top of his tank
When did you start noticing the symptoms?two hrs ago
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?6 months

I suggest getting a liquid test kit to measure your cycle, do more water changes, and depending on his water schedule change in his original tank, someone will recommend a treatment for you. It sounds to me like he has been suffering from a lack of water quality.

 

what kind of water conditioner are you using? some are better than others for removing high amounts of chlorine like you said you have. if you aren't using it already, i would recommend Prime. it does more than remove chlorine.

also, if he was in a 1/2 gallon bowl up until a day ago, and you were only changing the water every 2 weeks, that is not near enough, and he could have several problems resulting from that. for a 1/2 gallon he should've had the water changed every day.

it's good that he is now in a nice big 10 gallon! however, if it is not properly cycled yet, the water parameters could be all over the place, which could have killed your other fish, and could make him sick.

i don't know much about cycling, but a lot of people here do. but it's a big process, that if you don't do it right, can really harm your fish.

good luck, and hopefully someone can help you more than i can.