for level in {0..8}
do
    flac --verify -$level -o tam818.$level.flac tam818.flac
done

$ stat -c '%s %n' *.flac | sort
232049 tam818.8.flac
232406 tam818.7.flac
232845 tam818.6.flac
233596 tam818.5.flac
233596 tam818.flac   # so original was level 5
234490 tam818.4.flac
234991 tam818.3.flac
241091 tam818.0.flac
241091 tam818.1.flac
241091 tam818.2.flac