I would take those plants/leaves out of his bowl. You have no way of knowing if they've been sprayed with anything. I don't know what size the bowl is but if you have a 2 gallon or larger you could add a heater. I have all my bettas in critter keepers with heaters in them and they do fine. I hope this helps.
Sooooo, I'm a teen. And my mother just bought my little sister a beta. Yesterday, he started looking ill(white on his bottom). The night before, he had a tank cleaning. I assume he's ill from the tank cleaning and that there is too much ammonia in the water. To treat this, because I personally do not have any money, I've been adding a lot of the StartRight conditioner. I believe overdosing on anything is bad, but I don't want little Leo to die. My mother added an air filter and we've dipped leaves from a neighboring plant into his bowl for more oxygen, but now it seems he's gasping for air MORE. What is a cheap, but lasting fix to this? I can't afford much, and neither can my parentals. Please help. Thanks! And also I don't know how to post things and your profile says 'Super Moderator' so you seem legit.