i have a beta that i keep right now in a simple glass vase and a lilly on top, and he dose ok but his vase still gets pretty dirty. And the constant movement of the plant seems to be kill the plant in the long run. So what im asking is, would it be good or bad to put the beta in a small tank with a tank filter??
Yes it is safe to put in a small tank but he would have to be without tankmates of course. The pet store that I buy from has been able to put them in with some nonagressive fish but unless you're sure they wouldn't pick on him I would only have him and some plants in the tank with moderate water flow.
We used to keep my son's beta in a one gallon tank that was all inclusive. They are very inexpensive but have the filter system. It gives one beta a much larger, more enjoyable water world and the filtering system means a cleaner tank with less work for you.