Long post! Before I begin, let me explain a bit about myself. I have been keeping fish for many years, though I am very new (and bad at) plants and shrimp. I have kept clown and zigzag loaches, spotted and dwarf puffers, albino cories, arowana, african cichlids, jack dempsey, needle gars and bichirs, all except the cories and dwarf puffer in a 185 gallon tank (not all fish lived there at once). I've also managed the fish section of a pet store and have gotten to volunteer at a local aquarium+pond store. I currently have a 20 gallon long community tank, a 4 gallon scarlet badis tank, a recently broken down but still running 10 gallon that just has sand in it, and a plants-only 9 gallon cube. I also have a breeder box on back of my 20. That being said, I have decided to add 2 female betta in with my community tank, along with my current male. I am hesitant to do this because its not recommended given bettas temperaments, but I have a weirdly agreeable male. I am also fully prepared with space and meds incase anything happens, and I am aware that my fish's health is more important than my entertainment and I will not hesitate to pull a fish to keep them safe. [[more]] Before I got my male koi plakat, Crispin, I had pretty bad territory issues in my 20. I have a bonded couple of 2 glo danio (zebra danio) that dominated the tank, along with 3 aggressive halfbeaks that were starting to hurt each other during their surface territory disputes. The kuhlis and corydoras I keep had/have no issues because they're perfect angels. As soon as I put Crispin, everything balanced out. He established his territory (everywhere) and the rest fell into place with their own. The danios stopped fighting the halfbeaks and chasing them, the halfbeaks stopped beating the hell out of each other and are now all growing because they're not stressed. Crispin actually interacts with the fish. He plays tag with the male danio and even schools with the habrosus cories when they do their synchronized ballets. I have never once seen nip or chase. I've never even seen him flare! Not at the betta next to his cup, not at the other fish, not at his reflection-never. So last night, I got in my order of 3 female plakat bettas. A red/black koi i've named Penelope and 2 small unnamed sisters, one red and one yellow koi (small as in the size of my pygmy cory and a third the size of my male). Penelope I put in the 9 gal cube by herself, for now. The other two girls I floated in clear containers in my 20 for about an hour and a half before releasing them. My fish paid no attention to them whatsoever, except to initially inspect the container. I released them and have been observing them closely for the last 24 hours. The red and the yellow have established territories and I have seen them chase and flare amongst each other to defend them, but no contact or follow through. In the open areas away from their zones they swim together/near each other peacefully for the most part. Both are really into the cories and the yellow one moved in with the kuhlis and rests next to their noodle pile. Crispin mostly ignores the girls and treats them like the danios and halfbeaks; they don't exist until they're in his space or by his food, then he half heartedly chases them off. I've seen him chase of the yellow until shes out of his zone then he lets her go, but twice i've seen him chase the red one around the whole tank but always staying an inch or two behind. She seems bold and pushy though, she swims into his zone on purpose. Still no flaring from Crispin, or from the girls toward him. He still spends most his time dancing with the cories or trying to get my attention. So far, my biggest concern is the red girl. The yellow girl seems pretty content and peaceful, she mostly meanders through the vallisneria pecking for food or watching the kuhlis (she is fascinated by those wigglers). She is definitely the bigger and dominate one of the sisters, and gets the Good Surface Spot during feeding time and chases the red one away from the vals. The red one explores the other 70% of the tank, the open areas and the corner with just a heater sand. Shes kind of nosey and awkward and gets in the bottom feeders space or wanders into the danios and halfbeaks territories a lot. But she definitely pushes it with Crispin, and purposefully goes in his space or follows him. I'm worried when she gets bigger she will challenge the yellow sister and lose, or challenge Crispin and maybe actually make him flare for the first time in his life. If she starts being a danger, I can put her into the 10 since its cycled and running. I'm going to keep this situation as long as I can but I am looking to buy another tank and do a proper sorority in the future. In the meantime, I am 110% prepared to remove any and all the bettas if I need to to keep them healthy. My fish's health and happiness are my top priorities and I have the cycled, heated and filtered space for them ready just in case. I will be keeping a regular written journal (I extensively journal my fishkeeping) and posting updates on here, and if it fails I will make a post about that with a breakdown of why and what I did to remedy the failure. I cannot stress enough how important my fish are to me and I'll take them out even today if I see anything suspicious. Thanks for reading! Wish us luck!