I am trying to get a school of cardinal tetras in my tank but I am having no luck. I got 6 a few weeks ago and only 2 lived. Yesterday I got 6 more I floated the bag for 30 minutes then dumped them in to a net then into my tank. This morning only 2 of those are left. (The 4 dead ones are in a bag in the freezer until I can get back to LFS to swap them for living ones) LFS said they don't transition well and that once they are acclimated they are easy fish to keep. But how do I get them to survive the transition. Is there a secret that I don't know about?