are bettas agressive from birth?

[Weaver]

Hi
I got 3 bettas through the post today from bettaman. I was only expecting 2 but he sent a free one (God bless him)
However this means Im kinda stuck for space until the sealant sets on the dividers in my new tank--probably sometime tomorrow night
Couldd I chance two of them together in the meantime or would I be better housing one in an old 7 litre wide mouthed goldfish bowl (unheated)
They are all about 2/3 months old and still quite small?

 

[Kiarra]

From birth? No. Not until about 6 weeks of age do they start getting nippy with each other, and some take even longer.

Yours are more than 6 weeks old, though, or else they wouldn't have been able to be shipped. They're probably at least 10 weeks old, making them 2 1/2 months old, at the least. Which makes them unsafe to put together, because they might honestly be fine at first, but they might tear into each other while you aren't looking. It happens.

Go ahead and use the unheated, unfiltered tank. Just make sure you keep it covered (Bettas are wonderful jumpers, for no good reason), and keep it in a place that has fairly stable temperatures that don't get below 70 degrees Fahrenheit. 7 litres (which, if I'm not mistaken (which I might be, and please feel free to correct me if I'm wrong), is about 1 3/4 U.S. gallons) is actually a fine tank for a Betta as a permanent home, as long as water quality is maintained with at least a weekly water change, and twice weekly would be even better.

 

[nashnut]

I've found that they're nippy quite early. However, what I really noticed is that once you've done any type of separation and given them their own space they become much more aggressive.

Poor boy was in the grow out tank with just a tiny nip here and there. I moved him over to the separate quarters along with a couple others. He managed to get into the next guys compartment about a week after the move. Here's the result.
Remember these two were swimming together in the same tank days before without any major problems.

 

[Weaver]

Thanks for advice
I will keep them seperate until the tank is ready
Hope your poor fish recovers nashnut

 

[nashnut]

He's a happy little clam now with new fin growth... took this about a week ago.....

 

[GuppyDude]

your bettas will be fine in anything, as long as they arnt together. its not gunna be long untill your dividers are done anyway. the heater wont be a problem, just move his bowl somewhere warm in your house, he'll be fine, i dont use heaters with my bettas, even in the winter time. Gl