You could get a betta with those fish, but if you only cycled the new tank for 2 days, I doubt if it fully cycled. Did you use any of the water and articles from the 10 g tank or is the whole thing new? Before you add anything more, make sure the tank has cycled properly, otherwise you'll get ammonia and nitrite spikes that could kill your fish. Also, is the swordtail male or female. Betta's have a penchant for flowing fins and one might find the tail of a male swordfish rather tempting and attack him. There should be no problems if the swordtail is female.
Well, I am new to these forums, but I am not that new to fish I have had a 10 gallon with guppies, well, those lasted for about a year and my mom currently found an awesome 20 gallon with a stand for real cheap and she bought it, well, I cycled it for 2 days, and added my three fish, I had a swordtail left over from my 10, one of the only ones who made it threw everything. I added, 2 clean up fish as well, I just gave it a nickname as a sucker, and I forgot its real name, Shame huh? Well, I also have this catfish that was in the same tank. I bought these fish from walmart, but I should really say I rescued them because of there horrible keeping. The swordtail had been in horrible shape and I raised her to be a good fish, could I get a Betta with that sucker, and cat fish looking fish.
