Sick betta fish

Question
My fish, Bella, seems to be fading away in her activity.  She used to be very active but now just is not swimming around much.  I've had her for less than 1 year and bought her from PetSmart.  Her belly is enlarged as well and she is swimming (when she does) very close to the bottom of the tank, nose down.  I am 9 years old and need your help, please.

Answer
Hi Karlie,
Sounds like Bella could be suffering from several things. Its difficult to pinpoint the exact cause with little info about her environment and overall care.

Low temperatures (at 70F or below), polluted water, and constipation come to mind. Make sure with this winter season, that her way is kept in the mid 70's range. This can be difficult in a small container because there aren't really any heaters small enough for a small volume of water. Which is why aquariums are better for bettas in general. If Bella is in a container too small to heat, the best thing you can do is try to put her in the warmest spot of your house... Don't overdue it though-- keep an aquarium thermometer in her water to keep track of the temp.

Polluted water is a very common problems for bettas kept in small bowls and other little environments that become dirty very quickly. The best to do in this case would be to change at least half of the water every day. Make sure the new water temperature matches the original water temp or just a tiny bit warmer...not colder.

Constipation can make a betta's belly become bloated and cause lethargic behavior. Overfeeding and not enough variety in their diet is the primary blame. Even though betta pellets 'claim' they are complete. The majority of bettas need some variety in their diet to keep their digestion working properly... this can come in the form of alternating between frozen brine shrimp or bloodworms with pellets or flakes. You should try to presoak pellets and other dry foods before feeding as well. To treat constipation, feeding green peas and holding off on the betta's normal food for a few days can help. Most bettas accept little bite-size pieces of green pea just fine... if Bella doesn't-- try some frozen brine shrimp or daphnia. You can find these foods at the frozen food section of your local petstore.

Look here for more help also -

nippyfish.net

I do hope this helps!
Karen~