The difference might be in the acclimatation. How did you do it ?Surprisingly I started off with 13 neons and a few months later still at 12. 1 died within a few days. It's such hit or miss with them. They're all getting big and plump now compared to when you buy them and they're so skinny and malnourished looking.
Put the school in a 3 gallon bucket with the original LFS water.Where were the fish while the slow drip took place ? Did you manually pour or use some kind of automatic tool ?
I think so too. I might give it one more try, this time buying 12-15 of them at once.I think the other key was getting them in a large group too.
Great tip, thanks !