If you observe that they have problem with melting, you might want to check your GH level. If GH is too high, Water change can help to lower it. Also, check whether there are any rock in your tank which may cause the increase in this parameter.

I just started my first tank about a month ago. It's planted and was doing great, so I got 5 more cherries. I just found 2 dead today, both my older black ones, and it looked as if they had trouble molting. However, their front "head section" turned bright red. Why did they die and what can I do about it? I don't know what I'm doing (or not doing for that matter).
Please help.
If you observe that they have problem with melting, you might want to check your GH level. If GH is too high, Water change can help to lower it. Also, check whether there are any rock in your tank which may cause the increase in this parameter.
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