Originally Posted by finnfinnfriend
Well what if it isn't cycled?
But it is cycling. You haven't been doing 100% water changes. With an ammonia source (your betta) the bacteria colony will grow whether or not you want them. I can pretty much guarantee your tank is in the cycling process unless you have enough live plants in there to offset the ammonia production by your fish.
If you don't want to cycle your tank, I suggest you bump up your water changes to twice a week and make them about 50% to 100% of your water volume. Even then, your tank will still try to hold a cycle. It's the ecology of the aquarium. Tanks with enough surface area to hold the bacteria cycle whether or not you want them to. The only thing you can attempt to change is the harmful effects on your fish.