Originally had kribensis with 4 corydoras in 29 gallon tank. Kribensis was very happy would see him a lot especially at feeding. Then I added 6 neon tetras, kribensis was a little aggressive towards neons and had a bad die off them leaving only 1 neon left. 3 weeks later added 7 neon tetras and they have all survived so 8 total. Since the new neons have been added the kribensis has been hiding a lot, doesn’t even come out at feeding. Water conditions are good 0 ammonia 0 nitrites 20 ppm nitrates. I change water weekly. I thought maybe there would be some initial stress but 1 month later he’s still hiding. I was hoping to add more neons and corys to make them happier but not if kribensis is going to stay unhappy. I didn’t want to get another kribensis because of aggression in the community tank but otherwise don’t know why he is acting this way.