Ok..Well so many people have told me that you CANNOT keep a Male beta nor female beta in with guppy or fish with flared tail's, nor could you keep a female and male beta in the same tank together unless mating them...I had just a 20 gallon tank for 7 month's that included...One fantail gold fish, 1 Balloon fish, 2 fancy tail guppy's, 1 male normale guppy, 1 gaurmi, 2 irid shark's,2 female Beta fish, 1 male beta fish, 2 headlight tail light , 2 albino bueno's tetra's, 2 neon tetra's, 2 serpent tetra's, 2 bala shark's...As the fish got bigger the fantail gold fish , the 4 shark's ect i upgraded to a 55 gallon tank...And in that 55 gallon tank i have all those fish still in it lacking the 5 tetra's by choice left them in the 20 gal tank to give all of them enough room ands space to roam and be happy.. Never once in the total of 11 month's have i ever had a problem with my beta's being together nor them being with any of my other fish.. Don't get me wrong because i no it does depend on the fish because my brother lost his female beta and his 4 molly's due to his male beta killing them off, i just got lucky ..But it can be done, but even myself knowing it can be done DO NOT RECOMEND IT..Unless you as i did spend hour's just stareing into your tank and at your fish to watch and protect them encase they did not get along, Even 11 month's later i still keep a very close eye on them because they could turn on each other at any given moment.. Hope this help's a little...