I need some advice

I need some advice

I currently have a 10 gallon & and a 5 gallon aquarium- but recently came into possession of a 15 gallon. I’m between two options 1: Moving my Betta from the 5 gallon to the 10 gallon and my small tetra colony from the 10 to the 15 gallon (there are 6 blood fin tetras in there currently) and then doing something with the 5 gallon OR 2: keeping everyone where they are at and stocking the 15 gallon

If I do option 1, what should I do with the 5 gallon? Could african dwarf frogs be an option? and could I add more to the 15 gallon with the 6 tetras? If I do option 2, what would you recommend for the 15 gallon?