I have a new betta sorority that was set up last week.
15 gal tank
Filtered- mesh over filter since a few girls decided to jump in
Inhabitants: 6 female bettas, 10 ghost shrimp
The water parameters seem good-- the tank experienced a little bit of a bump in ammonia/nitrite right after I added them all, but I've been vigilant with the water changes and it seems to be fairly even now:
Last test had undetectable ammonia and barely detectable nitrite (right before a water change). pH is about 7.6-7.8.
The ghost shrimp appear perfectly healthy and active, and were quarantined with other fish (guppies) for two weeks before being introduced to this tank, so I don't think
they could have brought any fish diseases with them. If it were a water quality thing, I'd usually expect shrimp to show it first.
None of the fish seem to be sick exactly, they just seem to be a bit lethargic. They spend most of the day sleeping, and only really move around a lot during feeding time. I'm used to male bettas who seem to be constantly on the prowl. Their fins seem kind of clamped when they are sleeping, but they spread out when I see them swim or go for food. One of the girls in particular-- the smallest one-- seems to be shedding her slime coat quite a bit though.
Could this be caused by the stress of a new sorority establishing itself? I haven't witnessed any fighting, but I have noticed some torn fins a couple of mornings (no major damage or body damage).
I think they have enough room to hide from each other. They seem to mostly have separate territories, and I have added some more plants to help break up line of sight.