Hi Pwnisher - My experienced answer for you would be don't it. Not worth even trying it. I owned guppies in my 25 gal. I only had 5. They are HYPER and constantly bugging each other. Swimming a ton and bugging everything else in the tank. I had already removed my sorority at that point and the guppies were my next purchase. They were almost worse than the sorority - fighting, nipping, bugging, etc. I would never consider putting them in with bettas. The bettas will either completely stress out and either attack them viciously or hide and never come out. After a while I removed my guppies because I couldn't handle the stress in the tank. I did tons of research on them and all the seasonsed guppy owners state that guppies should really be housed alone, and only if you intend on breeding. Yes, they breed like mad and are worse than cherry shrimp when it comes to reproduction - another factor you'll need to learn a lot about. Also, if you just get males, they will eventually fight to the death. They are bred to breed, so that is their main motivator in life. A lack of females causes them to turn on each other. If you have males and 1 female, they can even accidently kill her by just bugging her death ie. bumping her, following her around, etc. They're a pretty hyper, active bunch of fish. I would just reccomend doing a lot more research before owning them and certainly I wouldn't house them with bettas.
Thank you for the advice. I'm only experienced with Bettas but I've always had an itch to have a tank with some male guppies. I'm glad that I now know that they don't mix on any level and whatever the combination.
It was such a bad experience for me, that I don't wish it on anyone else. I too enjoy guppies. They're so colorful and such pretty little fish. I had no idea their level of energy, nor did I know they were breeding machines! Betta Sororities require their own attention, as I learned that the hard way too. Have you ever tried a sorority? If this is your first, the best option is to get females from the same fry. If they've grown up together, you'll have a much better success rate. Worst combo is to just go to Petco and buy random girls. They *will* fight each other and sooner-than-later you'll have a room full of individually cupped fish. Many of us have tried sororities and have good success for a time - some for a long time! But pretty soon the fighting begins to escalate and it gets to you. Best idea is to contact a breeder and see if you can get a handful of sisters. That's my next project, coupled with breeding. Be sure and post pics. We all love to see the girls together!
Maybe in a 2 gallon. I don't know. They're schooling fish so they like company but at the same time, I've had other people tell me you can keep only a few in a small tank, like 3-5 gallon. I was actually wondering kind of the same thing myself. But in all reality, I'm pretty sure the only things that can safely live in a 1.5 gallon are bettas, African Dwarf frogs (one), or ghost shrimp.
That's the sad part about bettas is their short lifespan. But like so many things, it does have that plus side that you can experiment with other fish too. You aren't making a 15 year commitment like you would with an Oscar cichlid.