What Large Fish Would Work With These?

[mark.w.jones]

how about a male betta and 3 female, would certainly add a bit of spice

And carnage

 

[rdd1952]

how about a male betta and 3 female, would certainly add a bit of spice

That would eventually free up more room as the male betta would kill the 3 females as well as the 5 guppies.

In the tank you have, you really don't have room for a "big" fish. Of course, that depends on your definition of big I guess. A tank your size really isn't suited for any fish that grows to more than about 5 or maybe 6 inches. Also, most fish that are larger and can be kept singly will also eventually eat your smaller fish.