Hello, welcome to the forum :)
I think as long as you have a nice tank, heated, and water changes are done enough, you should go ahead :)
There is a lot you can learn about bettas, so check around the site.. How big is the old tank you are planning to use?
Many people here suggest at least 2.5 gallon tanks or larger. This reason being it is easier to heat, and water changes are a bit less than a smaller tank, like 1 gallon.
I started out with some bad experience myself with bettas, but I've gotten so much better, and I must say they do get addicting!
Once again, welcome to the forum :)
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