I do highly believe it was from ammonia poisoning. Based on your measurements, your tank is about a gallon. This is too small to keep a betta in. Bettas need at least a 2.5 gallon tank. In a gallon tank you need to do daily 100% water changes to keep the ammonia levels down.
Please for the love of God. Get a tank atleast 2 gallons or more with a filter and heater. I had my new girl in 1 gal for a week and the tank gets so filthy its insane. I got her a nice 3.5 gallon tank with a heater and filter today on sale for only 22$ at petsmart. They also had a regular 2.5 gallon tank with nothing but the tank but for only 12$!
Buy another Betta and start over, Im sorry for your loss but you learned your lesson.
Excuse me, but bettas can eat peas, just not all at once. The same goes for cucumber. Freeze dried blood worms are also totally safe for your betta :)
If you don't know, fish can't eat anything whole. They have to take bites, even if they don't have teeth. If prepared correctly, peas and cucumber for fish can save lives.
Bettas are Awesome change his tank water often. I believe all the ammonia in the tank is why your betta is sick.
I agree that peas are fine if fed sparingly for constipation. The interesting fact is that hardly any animals (and I say hardly any because there may be one odd species that I'm unaware of) can digest cellulose (plant fiber) by themselves - animals simply lack the enzyme necessary to cleave the linkages between the D-glucose molecules that comprise the polymer. Herbivores generally have a cecum that harbors beneficial bacteria that CAN break down cellulose into its glucose monomers, which the animal then harvests for its own use. Humans do not have a functioning cecum (the appendix is a vestigial cecum), and thus are relatively unable to digest cellulose; this is why fiber is used as a bulking agent for our stools, producing a laxative effect.
Indigestible fiber, fed in moderation, should not harm the digestive tract of a carnivorous fish just as it does not harm the human digestive tract. Remember, we are talking about feeding a pea once to help with constipation, and if the treatment works, this may save the owner from having to resort to more severe treatments (which are definitely unnatural). By all means try daphnia first (it is a better source of nutrition as well), but if this fails I see no reason not to try a tiny amount of pea. Of course, feeding peas in abundance could definitely cause issues since the digestive tract is not designed to handle large amounts of plant matter; nutrient deficiency could also become an issue if plant material makes up large amounts of the diet (which is also a reason to avoid low quality fish foods). However, in searching through scientific databases, I cannot find any scientific evidence that a pea would be harmful if fed sparingly to treat constipation.
There is no pet smart in hk and my home is not big enough for a bigger tank
Besides there are even smaller tanks and the person in the store keeps a betta in the same size aquarium and it still has not died yet
Yogosans "I hope u have learned ur lesson dosen't sound very good"
But I have learned more about bettas and everyone says there is a pet smart but there is no pet smart in hk but there is goldfish street.
By the way a fish expert said that I should not change the water often
Sounds like they're giving you wrong information. Like someone else said, one gallon tanks need daily 100% water changes. They don't sound like a real expert, otherwise they would've warned you about the ammonia levels.
Bettas are VERY hardy fish, honestly too hardy for their own good sometimes. They can survive a lot and it tricks people into thinking they can be kept in less than ideal conditions. ):
Excuse me but daily 100 percent water changes don't sound too good
The bettas need time to adapt to the ph and whatnot if u do 100 percent water changes every day it would be like (for a human) moving to a different country with different air pressure whatnot everyday (like going to Beijing then to England than to Brazil then to Hong Kong then to New York everyday)