So I have an old tank and I want to put a betta in it but im not sure if it is big enough. I want to say its about 3 gallons and I know that everyone says to put it in at least five but its going to be the only fish in there (other than maybe shrimp or a frog). Is that going to be big enough for him? It comes with a filter but im not sure if it is the right size. What is too much current and that for a betta? How do you know? Plus can you put a heater in there? I was also thinking of putting him in a 7 gal hex tank but i want to put other fish in that one. Any suggestions or ideas for my betta? (I dont have him yet i will only get him after the tank has been cycled). And for cycling the tank i dont want to keep the fish i get to cycle the tank to stay with the betta because i dont think thats enough room. What would i do with those fish? I dont want to throw them out or put them in the other 7 gal tank. Ugh so many questions and i dont know where to start!