The issue you are having is in how you are cycling over your hash. foreach my $lig (%{$ligHash}) converts the hash into a list, alternating key-value pairs. I believe what you mean to use is: 

foreach my $lig (values %{$ligHash})
{
    DoDump($lig);
}

[download]

This will feed only the sub-hashes into your subroutine (see values).

Regarding memory usage: Today, 6.5 MB is not all that much, unless you are using legacy hardware or developing toward mobile apps. The definition of "a lot" depends strongly on application.

Update: After reading almut's post above, I have to ask what is your expected output? Please read How do I post a question effectively?. Clearly two monks read your post and drew opposite conclusions as to your intention.

In reply to Re: Problem cycling through top level of nested hashes by kennethk
in thread Problem cycling through top level of nested hashes by tomdbs98

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