Every tank has bad days, where plants, scaping, or fish are far from their best. Here is my 15 gallon high betta sorority tank on one of its worst days – after a huge loss of plants and an intense battle between the bettas over hierarchy upon the death of the previous queen.
My watersprite had formed such a dense, thick forest that light was unable to reach the bottom regions of the tank. All of the lower plants began to rot, as did the bottom portions of the watersprite itself. The rotting caused tank parameters to worsen, quickening the decay of all the other plants in the tank. Within a week, this tank when from a thick jungle to a barren landscape. For a betta sorority, the sudden loss of shelter was a dangerous situation, which did not end well.

All four female bettas after the battle for ranking. Now they’re fine together and show no signs of aggression toward each other. That was not the case earlier on this day.
This tank has four bettas, all seen together in the above photo. At the beginning of the week there had been five. The fifth was my first female betta, who I purchased when rather old and full-grown. She was the ruler of the tank, keeping the order among the sorority. When she passed, the remaining four bettas were left to establish a new hierarchy.
In a properly setup betta sorority tank, there would be so many hiding spots and broken lines of sight, that the fighting for dominance would mostly end at a chase. With the sudden loss of dense vegetation to provide cover, this battle for ranking became brutal. During a single workday, the bettas had a brawl that left me horrified upon returning home. Here are the results from that day.
The New Sorority Ranking – Post War of Tank Dominance
First Place – Red Betta
This darling gal is the top dog in the betta tank. She’s finally in charge after years of having to play second fiddle to the previous queen of the sorority: the late but once great betta who passed earlier this week. At first look, she seemed largely unharmed. Then I saw her left side. I’d never seen damage like hers before – it was like she’d been punched in the eye by a betta fin of steel. Getting a photo of it was ridiculously hard, but the swelling can be seen in the photo with the blue arrow pointing to the left side of her face.
Second Place – Blue Crowntail Betta
This little lady was added to the tank when quite small – less than an inch and barely old enough to sex easily. She was originally the most skittish and shy, always hiding BUT willing to fight off or chase away anyone who came near her hiding spot. This week, she decided to play hard in the fight for tank dominance, receiving the most extensive fin damage of any of the bettas. Definitely not the winner, but second best was enough to make her feel confident being out in the open all the time. No more hiding for this gal.
Third Place – Red and Blue Betta
This newcomer to the tank suffered only a gash on the top of her right front side. The scale were stripped, which could have either happened in a fight or while fleeing from one. She largely ignored the battle, but wasn’t willing to let the fighting alter her schedule of searching for food or swimming about in the open, hence the damage. I’m still not sure she knew there was a fight for ranking, but somehow she still managed to keep out of last place.
Last Place – Blue-Eyed Pink (Red and White) Crowntail Betta
This little lady spent the battle out of sight and out of mind. She doesn’t have a scratch on her, and would rather just ignore a flaring female and swim away than start a fight. This makes her my favorite in many ways – that and her beautiful tail and eyes! She’s a darling who will eat from my hand calmly. I’m glad she didn’t get hurt.
Aftermath of the Aftermath
Since the fight, I watched all of the bettas closely for signs of infection or worsening health. Water changes were performed daily to keep the tank as clean and conducive to healing as possible. Any further flaring or signs of aggression resulted in a betta timeout in the clear plastic cage on the left side of the tank photos. No further battles have been had in the two months since this original battle, and everyone has settled into their new spots well.
Betta sororrities can be difficult to maintain and start! You really need to have four or more bettas together to spread out the aggression and keep a healthy hierarchy structure. If I had been home when this was happening, I would have been able to add more decor etc to the give more hiding spots and broken lines of sight, maybe preventing some of the injuries. Had the aggression not already subsided by the time I got home, I would have changed the stocking of this tank. Every betta sorority will have some fighting/chasing when establishing the rank, but keeping it to a minimum and safe level is the job of the tank owner.