okay, So I've finally got all my girls together in the 29g. I guess I'll start a log so others can learn from my experience since sororities are very popular on this board. I think the idea of having more than one betta in a tank and all the color variety they can bring to a tank makes it all the more appealing.
So about 2 weeks ago I started collecting females. It is interesting since I live in North Phoenix just half a mile from the belt loop freeways. petco's and petsmarts are plentiful if you have a couple of hours to blow. In 3 days I visited about 12 stores and only drove about 50 miles total. Basically I was window shopping and if I found an extraordinary female I'd take her home. At the end of three days I had 7 females of your basic colors. 3 variations of blue, 1 green/teal, 1 red, 1 black/peach blended color, one pink/rose colored. I kept them in their cups, doing 100% water change every 36-48 hours. Since they lived this way at the store I figured another week wouldn't kill them. I started venturing online. I ended up purchasing a couple more females from a couple of breeders here in the forum. and 3 females on Aquabid from 84elmo who I actually confused with a breeder from the same area in LA here on the board thinking I was buying from her :(. So after waiting another week I finally had all my girls. I kept them all in cups monitoring which ones were agressive through the week and the ones that were delivered I had to watch carefullly since I had a lot less time to observe. I knew I had one really really agressive blue/red female. She was the only one constantly flaring and stressing out of any of them. Most were calm and collective. I did not pay attention but when I'd fine a few sisters of the same color at a store I would not take them like I would males where you look for agression and alertness to gauge how healthy he is. I went with responsive and skiddish. That method really helped I believe in the overall demeanor. i really only had to add the agressive one last and the rest really didn't matter to me.
So the moment came to add them, basically would pick two, float them for 10min mixing tank water with their cup water so they get better acclimated. I would then add the 2 into my breeder box, then float the next 2. This allowed me to really see if they would acclimate well to the water or I'd need to QT them more or not. I rushed the QT I realized I probably needed to keep them all in their cups for at least a week or two more but I was willing to risk it. As they were added the all would venture around a bit looking at the plants, the CO2 bubble grid, The cycle guppies were a great welcoming committee as I think they really dispersed any agression the bettas may of had against each other. The last of the girls was finally added and man it was fun to watch for the next however long it was. I don't know maybe 50-60 minutes.
So this is what I watched for, flaring and staring was going to happen. Pecking order was going to be established and I was curious what so many girls would do. I did not have plants grown higher than 60% of the tank heigth, but I have the large Penn-Plex castle on one side and a good sized piece of drift wood on the other half that give a lot of hiding spots if need be. The plants are dense enough to break line of sight if they chase below the midpoint in the tank. So I crossed my fingers and Hoped for the best.
After reading all the horror stories of girls fighting to the death or stripping each other of all their fins I was prepared with my breeder box and net ready to quell any tensions. Well turns out any time the girls even got into a staring contest a male guppy would swim in front of them and wave his little tail like a bull fighter in Spain. It was hilarious!

People were 50/50 about guppies and bettas but man this was sure fun to watch. They would get in there with them and do their little wriggle and shimmy their tail and the girls would forget about each other and chase after the don Juan matador. This must of happened like 3 or 4 times before the first real tussle happened. I think the male guppies realized that these females bite back. Only one had a little nip after 24 hours so they were okay. As for my females I had the one tussle where the girls locked jaws and took some nips at fins. The one agressive girl was bigger than probably 9/10 females and still every fight she would pick would get more beat up. Everyone else got along fine, no one else flared or got all huffy puffy with each other. Just this one girl. Finally after a couple breeder box timeouts in the corner I decided that I probably should just take her back. After the entire afternoon and evening of watching her chase guppies and other fish I just cupped her and put her in her jail cell for the night. I had to take her back no way was I going to let one girl ruin my sorority. I wasn't up to setting up my separate QT/ split tanks for one girl. I was planning my back up if i had 2 or 3 girls that didn't get along but just one, I took petco up on their offer and returned her the next day. Hopefully someone will take her home she had a pretty finnage and interesting blue/red coloration.
It has been a week and the only loss I had was the rose/pinky smallest female had a back deformity that I did not pick up on until after she was free swimming in the larger tank. She struggled to get around and I watched her and she passed overnight after the 2nd night. Was sad to see her go, she was the cutest little girl. Reminded me of like a pink powderpuff girl or something. Still nature happens. So now I'm down to 8 girls. The AB ones are larger and hang down near the bottom in their spots. 5 petco/petsmart girls all swim around the top like a school, its quite funny. The guppies stopped pestering the girls once the big male got one of his fins nipped on the 4th day. Everyone is doing fine but I have to constantly do a head count and look at fins to make sure nothing happened while I was at school/asleep etc...
29g, Its not fully established, after adding them I noticed the Ammonia would increase much more rapidly. I've been doing 25-50% changes every 3-5 days. Basically every 3 days I do an ammonia test and if its gets above 0.5ppm I change I do a 50% change, if its close to 0.5ppm I do a 25%. I've got ferts and CO2 for the plants but the stock light bulb I think is too low so the plants haven't taken full advantage of the nutrients. I add ferts once every 2-3 water changes since I don't want algae at this point besides the little patches i've seen on the decorations for my zebra oto.
sorry no pictures yet, I've taken some but I need to go through the hassle posting them. I barely have time for my fish. I'm in the middle of the term when every couple of days is an exam so I'll get around to it soon.
So if anything you can take from this is that prepare for the worst but sometimes everything goes nice and easy and you aren't posting an emergency thread of what to do with all your injured fish.