Petco has a habit of giving out wrong information. Since they are tropical fish they need heaters, unless you happen to live some place very hot or tropical. However, heating a tank less then 3 or so gallons is a bit challenging because the smaller ones for bowls are not adjustable and from what I have heard, they are always on whereas 25 watt ones are usually adjustable and will turn off when the water reaches a certain tempature. Plus something that small should have a water change about every other day so ammonia doesn't built up.
Is that red thing I see in the pic what you are talking about? The thing that is by the long dangly fins near her head (sorry, dont know what they are called)?? if so, I am stumped. Is it actually comming out of her butt or is it more of a growth, like a tumor? I'm thinking internal parasites which I do not think pimafix will help with. I "think" that is for bacterial infections..?
•Symptoms: Betta is losing weight but eating normally and acting lethargic.
He/she might dart or rub against decor.
•Treatment: These can be hard to fight and can get confused with the fatal disease Tuberculosis. Perform daily 100% water changes (if possible, for larger aquariums change 3/4). Make sure you carefully clean the gravel to remove eggs/larva. Aq.Salt does not seem to be affective against internal parasites. I find combining ES with an anti-parasite med is best. Treat with 1-2tsp/gal Epsom Salt combined with either Jungle’s Anti-Parasite Pellets, Jungle’s Parasite Clear Fizz tabs or API General Cure. PP is also effective against internal parasites.
•Symptoms: You may see parasites (other than ick) or you may not. Pay special attention to the area around the gills and fins. May dart and rub against decor, lose interest in food, lethargy, color loss
•Treatment: Some parasites can be treated conservatively with Aquarium Salt. For salt treatments, treat as you would with Ick. If conservative treatment does not work or if you have extenuating circumstances then there are a number of medications you could use. API’s General Cure and Jungle’s Parasite Clear fizz tablets are both affective ways to kill parasites. Do not combine with Aq.Salt.
•Alternative Medicines: I like PP for all stubborn external infections. It has never failed me, but it should only be used as a last resort.
You can try Pming Sakura8, Myates, oldfishlady or earthworm88. They are all good with diagnosing stuff