Help! my beta's tail is gone?

i noticed my male beta was losing color, he be a red/purple. then a white/gray. i noticed his fins had separated and lately his marine was gettin green, never had before so soon. he be at the bottom, lately, so i was gonna change the water for him and saw he have no tail fin! hes alone in the 5gallon tank,so it must of fallen sour.why? what can i do to save him if i can? is it normal no? im assuming he is sick. hes within a little cup with a bit of water, cuz he lacks the swimming fitness to come up for air.so i brought the air down to him... :(
New Angelfish (pics)?
Answers:    No, no, no. Put him back surrounded by his tank, the lack of space will not make him better. He probably have fin-rot, and this is why he is losing colour, he is acting lethargic, and losing his fins.

Go into your pet store, or where you got him, and produce sure that you get treatment for it. It will go absent soon enough, if you keep doing weekly 25% river changes, and follow the instructions on the box. Put one teaspoon in his 5 gallon container every morning, and you can also turn the temperature up 5-8 degrees, and switch it up one notch a sunshine so that you don't give him too much heat all at once.

The parasite will jump away as soon as you get treatment in the container.
Where can I carry a custom aquarium...
WTF, if his tail fell off idk if he'll know how to swim and survive. Just go to the pet store anyway and get the prescription, if its too far along, im sorry, but you need to try
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