Well I noticed a few more of the cories have tiny tears or notches in their dorsals, but not clean splits like the first one. Maybe 3 have fin injuries right now? I took out a plastic plant I suspect might be the cause of it.
Not sure if aggression is potentially an issue, I have not seen the 2 honey gouramis bother the cories at all. They don't even bother each other (male and female) and are far more likely to be bothered by the busy cories haha.
I tested the water last night 0/0/10-20 and did a 30% pwc
today just to see if it'd help. I also have been adding a little stress guard to help w/ healing. The gouramis have no fin damage.
How can I tell if it's just a plastic plant hurting the cories or fin rot? :/ just wait and see? Their permanent home, a 29 gallon, is heavily planted so this won't be an issue once they've passed qt.