## I don't know how you're getting values for $i, $j, $value
$hash{$i}{$j} = $value;

##</code><code>##

foreach $i (keys %hash) {
   foreach $j (keys %{ $hash{$i} }) {
      print $i, $j, $hash{$i}{$j}, "\n";
   }
}

##</code><code>##

push @array, "$i:$j:$value";

## to print:
foreach (@array) {
   print join (' ', split ":");
}