diff --git a/postgresql_backup/pg_backup.sh b/postgresql_backup/pg_backup.sh
index fae5843..221c0c2 100644
--- a/postgresql_backup/pg_backup.sh
+++ b/postgresql_backup/pg_backup.sh
@@ -54,9 +54,11 @@ for PREFIX in $DATABASE_PREFIXES; do
 
     # Perform the backup based on the specified format
     if [[ "$DUMP_FORMAT" == "custom" ]]; then
-      pg_dump -h "$HOST" -p "$PORT" -U "$USER" -Fc "$DB_NAME" -f "$BACKUP_FILE"
+      # Custom format and highest ZSTD compression level
+      pg_dump -h "$HOST" -p "$PORT" -U "$USER" -Fc --compress="zstd:21" "$DB_NAME" -f "$BACKUP_FILE"
     elif [[ "$DUMP_FORMAT" == "sql" ]]; then
-      pg_dump -h "$HOST" -p "$PORT" -U "$USER" "$DB_NAME" | gzip > "$BACKUP_FILE"
+      # Plain-text SQL backup compressed with gzip at high compression level
+      pg_dump -h "$HOST" -p "$PORT" -U "$USER" "$DB_NAME" | gzip -9 > "$BACKUP_FILE"
     else
       echo "Invalid DUMP_FORMAT for $PREFIX: $DUMP_FORMAT. Skipping..."
       continue