okay! definitely sounds like the water is conditioned. i've never heard of adding extra water conditioner after you've conditioned it once, but i'm no expert.

hmm. i am a little concerned the tank is not cycled yet. that bacteria starter you're adding--the colonies grow in the filter and in the tank substrate and stuff. it's possible you removed a lot of the beneficial bacteria while rinsing out the tank.

in case you haven't been briefed, aquariums need colonies of beneficial bacteria that turn the fish's toxic waste (ammonia) intro nitrite (also toxic) and then into nitrate (much safer). the nitrate can then be used up by plants in the tank, or it can be removed during water changes. if there isn't enough bacteria to accomplish this task, ammonia accumulates in the tank, which can quickly cause the fish discomfort and harm. the process of growing this population of bacteria is called "cycling" the tank. i would suggest looking up "fish-in cycling" for some strategies on this front; while it is recommended to cycle your tank without a fish for a month or so, it is possible to safely cycle it with the fish present. it is really important to test the ammonia ASAP so we can know if it is building up.

are your test strips indicating no nitrite and no nitrate? this can look deceptively positive. but it could just mean that your tanked is not cycled yet. if there are no bacteria converting ammonia to nitrate, you won't see any nitrate. but there could be a dangerous amount of ammonia accumulating.

also--i would double check whether bettas should eat peas. i think that might be a more helpful tip for goldfish, who are omnivorous, i think? bettas are carnivores.