I never found the secret to keeping one long term. I've bought several, kept a few of them alive and looking good for up to 6 or 7 months, then they just up and die for no apparent reason.
I know that most people will do what they want regardless of advice offered, I did it myself, thinking "Yeah, but, I know what I'm doing".
I didn't know what I was doing, and the odds are not in your favor........