Like I said before, my experiences with danios haven't been so negative but you are quite right that it's risky. Having seperate tank(s) ready for the betta(s) if you go for those is a very good idea in case things don't work out.
Anyway, I just wanted to say that I disagree about not keeping male bettas in larger tanks. I think this is a misconception that stems from the idea that wild bettas live in 'rice paddies' and all that. I have kept bettas in communities - both males and females - and they have all lived long healthy lives. If you think about it, letting the betta swim around more can't be bad for it. The idea that they get 'tired' or 'aren't good swimmers' and so forth is totaly unfounded as far as I'm concerned. I mean, they are fish aren't they

They swim... To be honest, I feel people have used this as an excuse to justify keeping bettas in very small tanks and it's just stuck as a result. I do, however, appreciate that a betta that has lived its whole life in a cup/jar and then is suddenly given free roam of a 55 gallon will feel nervous at first but, if you consider it, they are not so far cut from their wild anscestors that they cannot settle down and actualy do better with the larger space than if they are forced to live in a 1 gallon bowl for evermore. People have made it sound like they live in little puddles in the wild - they don't - they have hundreds of gallons of water in the wild! Just think of the expances of (shallow) water. But, for the record so to speak, very fancy betta varieties like super deltas and crowntails can have their fins damaged by the effect of swimming against the current or a lot of 'excersise' in a large tank - so bettas meant for show, for example, would be best off kept in a smaler tank. If you avoid keeping them with nippy fish though, and don't have a strong current, even the fancier types would be fine as community fish. I still agree that a male is not a good idea for your tank though.
Yeah, anyway, Anna, I always say that if you are a pessimist, you don't get dissapointed if you are wrong while if you are an optimist, if you do turn out to be wrong, it can be very annoying

. What I mean to say is that you shouldn't be apologizing for being negative!
