My sister and I started out with 1 10 gallon sorority and planned on putting Frog and the 3 girls we bought in it. Frog got sick before we could introduce her, so she was out for a little while. We qt everyone and when Frog was better, we introduced the shyest girl first (Lyra). She was good for the first 15 minutes until we put Sycamore in.
Lyra and Sycamore are eternal enemies. Any reintroduction with the two of them leads to constant quarrels and bites, which Lyra eventually spreads to everyone, because why not share aggression with everyone?
Frog, Elm, Oak, and Sycamore did well, but Frog was bullied a little for her size (She was stunted), so we started a second sorority for some smaller girls and retried Lyra. Turns out, docile little Lyra is a massive jerk. We bought a few giants from Walmart along with another tiny girl to try out, and the tiny girl did ok in the little sorority, but did good in the other one.
We put one of the giant girls in the 10 gallon sorority and the blue marble giant in the small one. Unfortunately both giants fell ill and passed away despite our best efforts of treatment. So we were left with a 4 girl sorority working well, and a 3 girl sorority with 2 jerks named Hester and Lyra.
We tried Hester in the big sorority, but that didn't work out well multiple times. Frog didn't work out because she kept getting sick (immuno compromised or something. Lyra didn't work out because she's a jerk.
Unfortunately, the little female that was working so well in the remaining sorority managed to get tangled in some plants while my sister and I were away and drowned. We got another giant to offset the aggression. That giant was named Tokyo and she became the alpha. She also passed away too soon, by way of a cat.
Unfortunately Frog, Oak, Tokyo, Chocolate, and Hester have all passed away. Lyra has to be kept solitary or in a divided tank with a barrier over the top because she likes to jump.
We added Sabino after Tokyo passed to try and offset the aggression once again and it has definitely worked, although there are still only 3 permanent girls since Oak passed unexpectedly.
We've bought 2 more girls from Petsmart and are slowly introducing them to sorority life. They're young, so I think they'll work out perfectly.