I really have to agree with LebronTheBetta here. I really couldn't have explained it better myself.
The bottom line is, your girls could be fine for now, could be find for several weeks....but they will fight. And they will seriously harm or kill each other. If you want to take the risk and wait until you have one or two very injured fish on your hands before separating them thats up to you, but I was well would very highly suggest you divide that tank ASAP before problems arise.
A homemade divider is very easy to make and instal and very cheap, just a couple/few bucks. http://www.tropicalfishkeeping.com/d...ividers-21866/
To make the divider a little more sturdy, use two sheets and double up on the craft mesh then do a little more precise measuring/trimming to make the divider fit snugly without the bend.
Make it, slip it in between your girls in the 5 gallon and vuala! Instant safe way to keep both your girls in the same tank without the risk of them killing or harming one another at any point. ;)
Shoot, though- it's a tall hex 5-gal- the plastic sheets are too small. I have it rather heavily planted w/ a cave, too, assuming each girl can have her own "territory". There is SO much conflicting info. out there about female bettas. Once source says 2 females are fine as long as the tank is big enough, and that smaller tanks cause stress and undue territoriality. These 2 do look silly- teeny fish in a 5-gal. I can't even imagine them fighting.
Well, the information in our site is based on experience and logic. Believe me, 5 gallons isn't even big compared to sir real territory. 5 and below tanks are considered nano tanks in the fishy world. Don't even forget about the ammonia. Please separate them, it's better for their well being.
Girls can sometimes be just as aggressive as males although maybe not right away. After establishing thenselves in a tank one or both might get really greedy for food and eventually one will come out on top. I see this all the time on my tank but since there are more girls the aggression is spread out and dies off sometimes in less than a day.. Because of this there are these long periods of "ceasefire" lol or peace.
If you want to have girls together, cycle a 10 gallon which is the minimum for a sorority and read the sorority threads ( I think there is a sticky). Either way, you will have to separate those 2 to prevent any scuffles....
Our info on this site is based on the experience of many very experienced keepers and breeders who have had and cared for bettas for many, many years. There IS a lot of conflicting information out there, as well as all the terrible myths and advice the poorly educated pet stores and their employees doll out, so we here on this site strive to provide proper information and advice to help people and their fish.
Your girls may not be fighting now, likely because they are a little young, but they WILL grow, they WILL mature, and they WILL start exhibiting aggressive behavior. These are an aggressive species that originate from a strain bred for for their aggressiveness to fight for sport; its not an issue of IF but WHEN.
Foot-print wise the hex is probably a little small to divide permanently, but you can 'sew' the craft mesh together with a bit of plain cotton sewing string or fishing line to make it taller; I've done this when dividing my larger 20 long and it worked out very well.
You can divide for now and start looking for other tank options. If you're working on a budget, check around thrift stores and Craigslist, you can often find nicely sized used tanks for cheap there. Another great money-saving tank option are Kritter/Pet keepers(medium-large). Just stick a heater in there, decorate it how you like, stick a lamp over it during the day(make sure the lamp doesn't get warm enough to effect the temp of your tank!)and you've got a nice little cheaper setup!
There are also lots of online deals on 2.5-5 gallon tanks I've been seeing crop up lately for the Holiday season, so you should be able to find something within a reasonable price range.
Yes, I read the sorority thread; that's when I learned the bad news... BUT it's the e-book I bought from this site that says female fish together are all hunky-dory! Maybe the book should be changed?!
A new question arises: how often can you change the fish from tank to tank? If I should separate the 2 baby girls ASAP, they'll have to go into a 2.5 gal (the one I have w/ a seperator built in) until I can buy and set up a 10 or 20-gallon! Won't this stress them out to the max??
(I know the 5 and 2.5 gallons are nanos, but I have them fitted with filters and heaters, plus live plants, so I hope it's better that other betta nano options!)
I can't imagine my female sharing her 5 gallon tank with another female, she definitely regards the whole thing as hers. She is aggressive, and would probably rip another female to shreds, even if I put tons of plants and hiding places! Mine is a hex tank too, and I couldn't even imagine her sharing it with a snail. She even flares more at her reflection than my male does.