You need to be doing more water changes! Like 50%daily at least. Pet stores sell betta in 8.0 ammonia when even .25 is dangerous, so their definition of ok is usually not ok. Also bettas shouldn't eat peas, only goldfish should. Peas will cause constipation, so don't feed him for a week please I beg you
Treatment: daily 100% water changes with 1tsp/g Epsom salt for 5-10 days then 75%daily water changes for the rest of his life. Small tanks are a lot more work than big tanks, so maybe invest in a 2.5-5g tank for less maintainance
Treatment: daily 100% water changes with 1tsp/g Epsom salt for 5-10 days then 75%daily water changes for the rest of his life. Small tanks are a lot more work than big tanks, so maybe invest in a 2.5-5g tank for less maintainance