Hi 2littlerevheads, welcome to the forum. Can you please fill this out? http://www.bettafish.com/showthread.php?t=49233
The info will help us know how to treat your betta. Also, you might not want to keep angels and tetras together. Angels eat tetras like potato chips.
What size is your tank? about a 10 liter tank
What temperature is your tank?n/a
Does your tank have a filter? no , it is just a fighter tank u get from a petshop
Does your tank have an air stone or other type of aeration?nope
Is your tank heated? nope
What tank mates does your betta fish live with? himself
What type of food do you feed your betta fish?
How often do you feed your betta fish?once a day at night
How often do you perform a water change? every 2weeks
What percentage of the water do you change when you perform a water change?half a tank
What type of additives do you add to the water when you perform a water change? water ager
Have you tested your water? If so, what are the following parameters?
Symptoms and Treatment
How has your betta fish's appearance changed? has not change
How has your betta fish's behavior changed? floating to the top of his tank
When did you start noticing the symptoms? about 3 days ago
Have you started treating your fish? If so, how? no as i dont no what to do
Does your fish have any history of being ill? not that i know of
How old is your fish (approximately)? n/a
It sounds like you might want to change the water a little more often in the tank. For a 10 liter tank, change the water twice a week, one 50% and one 100%. Ammonia builds up very fast and is toxic to bettas, that is what is making your betta sick. The only way to prevent ammonia poisoning is to do water changes to remove the ammonia frequently. I can't say if he'll make it or not but I hope so. Keep him in clean water and add 2 teaspoons of epsom salt. Let the salt dissolve in some water before you put it in his tank.
You are lucky, I'm glad your angels haven't eaten any tetras yet.
If you don't put him in the tank with them, get him a heater so he can stay warm. He doesn't need a filter but he definitely needs a heater. He needs to be in water that is about 26* celsius.