I got my first betta this summer, toward the end of July. This is the first fish I have ever owned so I'm kinda iffy on taking care of him. He's red with a hint of purple-blue at the end of his body and on his tail, I named him Aspen :D When I bought him my dad said a goldfish type tank and some silk plants and marbles would be okay for him to live in. I've also been told to change 90% of his water once a week, every week. I got him from petsmart, and they also told me to use to Fizzy-Bubbles stuff, that cleans tap water and makes it safe for him. Now I'm hearing all these other things on how to care for him. His tank is bigger than 2 gallons...I think it's about 3 or 4? But he has no heater or filter. I keep my room temperature at 78 for him. The first few weeks he was so happy, we would play with me all the time, and blew bubbles constantly. Now whenever anyone BUT me walks in the room, he puffs out his botton gill.

It kinda scares me and I don't know what he's doing. He doesn't really blow bubbles anymore, but he still likes to play hide-and-seek with me (he has about 3 silk plants in his tank) and blows bubbles when I see him. Once anyone else is near him he freaks. Can you give me some good tips so that Aspen can live a pretty long and healthy life? It would be greatly appreciated. :)
(he's so active it's hard to get a picture of him!)