Mangroves leafs turing brown

[hydrahawk]

I have about 21 Red Mangroves seedlings in my tank. During my recent move they were sitting in some tank water that is not heated (~50F). Now, they are in a 50G frag tank that is heated and lite (by natural and artificial). I noticed some of the leafs turned brown (dead), some of the tips are also turning brown. But I see new pink root growth in them. Does the leaf turning brown cause a concern with the new growth in the root system? How well does the mangrove do in freeze?

 

[Triterium]

No worries. I've grown mangroves Down to freezing. They recieved damage in the low 30s, but recovered (unheated greenhouse). 50 degrees isn't a problem. Moving them aroung is what they don't like. Brown tips is nothing to worry about, especially if there is new root/leaf growth.