I recently divided my 10 gallon tank in half. This is for space and practical reasons - I adopted a new betta and I'm trying to stop myself from being buried in extra tanks! Tempting though it may be :)
Now, the new addition to the tank is getting along great. He is active and happy, although of course the two spend a great deal of time flaring at each other.
My other buddy, though, is now sluggish and is showing stress lines :( I gave him about a month to adjust to having half the tank instead of the whole one and he was doing fine, but the addition of a new fish is really stressing him out even after a couple days.
I'm really worried about my second fish. He grew up alone in his tank - Will he adjust to having a tankmate, or will the stress be too much for him?