diff --git a/templates/prune_blocks.erb b/templates/prune_blocks.erb
index 5c182b0..19834d7 100644
--- a/templates/prune_blocks.erb
+++ b/templates/prune_blocks.erb
@@ -7,40 +7,40 @@ source <%= @ps_env_file %>
 LOG_FILE="<%= @ps_prune_log_file %>"
 echo "$(date '+%Y-%m-%d %H:%M:%S') Starting prune run" >> "$LOG_FILE"
 
-# Find all TSDB blocks
-TSDB_DIR="/var/lib/prometheus"
+# -----------------------
+# Iterate TSDB blocks
+# -----------------------
 for block in "$TSDB_DIR"/*/; do
     [[ -d "$block" ]] || continue
     meta="$block/meta.json"
     [[ -f "$meta" ]] || continue
 
-    # Get block min and max timestamps
     min_time=$(jq -r '.minTime' "$meta")
     max_time=$(jq -r '.maxTime' "$meta")
 
-    # Skip very recent blocks
+    # Skip last MIN_AGE_HOURS
     block_age_hours=$(( ($(date +%s) - min_time/1000) / 3600 ))
     if (( block_age_hours < MIN_AGE_HOURS + GRACE_HOURS )); then
-        echo "Skipping block $block (age ${block_age_hours}h)" >> "$LOG_FILE"
+        log "Keeping block $block (age ${block_age_hours}h)"
         continue
     fi
 
-    # Verify block is in PostgreSQL
+    # Check existence in PostgreSQL
     check_sql="${CHECK_SQL_TEMPLATE//\{min\}/$min_time}"
     check_sql="${check_sql//\{max\}/$max_time}"
 
-    exists=$(psql -h "$PGHOST" -p "$PGPORT" -U "$PGUSER" -d "$PGDATABASE" -t -c "$check_sql" | xargs)
+    exists=$(psql -h "$PGHOST" -p "$PGPORT" -U "$PGUSER" -d "$PGDATABASE" -t -c "$check_sql" | xargs || echo "0")
 
     if [[ "$exists" != "1" ]]; then
-        echo "Block $block not found in PostgreSQL, skipping deletion" >> "$LOG_FILE"
+        log "Block $block not confirmed in PostgreSQL, skipping deletion"
         continue
     fi
 
-    # Dry-run or delete
+    # Delete block
     if [[ "$DRY_RUN" == "true" ]]; then
-        echo "[DRY-RUN] Would delete block $block" >> "$LOG_FILE"
+        log "[DRY-RUN] Would delete block $block"
     else
-        echo "Deleting block $block" >> "$LOG_FILE"
+        log "Deleting block $block"
         rm -rf "$block"
     fi
 done