Originally Posted by Alienbetta1
Ummmm.........Could it just be the bettas though cause if I get a fish from walmart it usually dies 3 weeks later?
It could be this aswell. Really water is normally only the culprit in larger tanks (5g+) because those actually go through the cycle regularly. How big was your tank?
If it was a simple 2.5 gallon its possible the water wasn't treated well enough, but I'm leaning more toward it was your selection of the Betta.
I recomend calling petshops beforehand and asking them when they get a new shipment of bettas and go the same day or the day after, and maybe you'll have better luck.
KEEP YOUR CHIN UP :P