diff --git a/weed/worker/tasks/ec_vacuum/ec_vacuum_task.go b/weed/worker/tasks/ec_vacuum/ec_vacuum_task.go
index 450901105..5692f04a1 100644
--- a/weed/worker/tasks/ec_vacuum/ec_vacuum_task.go
+++ b/weed/worker/tasks/ec_vacuum/ec_vacuum_task.go
@@ -18,6 +18,7 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/pb/worker_pb"
 	"github.com/seaweedfs/seaweedfs/weed/storage/erasure_coding"
 	"github.com/seaweedfs/seaweedfs/weed/storage/needle"
+	storage_types "github.com/seaweedfs/seaweedfs/weed/storage/types"
 	"github.com/seaweedfs/seaweedfs/weed/storage/volume_info"
 	"github.com/seaweedfs/seaweedfs/weed/worker/types"
 	"github.com/seaweedfs/seaweedfs/weed/worker/types/base"
@@ -392,7 +393,7 @@ func (t *EcVacuumTask) mergeEcjFiles() error {
 
 	// Merge all .ecj files into a single file
 	// Each .ecj file contains deleted needle IDs from a specific server
-	deletedNeedles := make(map[string]bool) // Track unique deleted needles
+	deletedNeedles := make(map[storage_types.NeedleId]bool) // Track unique deleted needles
 
 	for _, ecjFile := range ecjFiles {
 		err := t.processEcjFile(ecjFile, deletedNeedles)
@@ -421,35 +422,39 @@ func (t *EcVacuumTask) mergeEcjFiles() error {
 }
 
 // processEcjFile reads a .ecj file and adds deleted needle IDs to the set
-func (t *EcVacuumTask) processEcjFile(ecjFile string, deletedNeedles map[string]bool) error {
-	// TODO: Implement proper .ecj file parsing
-	// .ecj files contain binary data with deleted needle IDs
-	// For now, we'll use a placeholder implementation
+func (t *EcVacuumTask) processEcjFile(ecjFile string, deletedNeedles map[storage_types.NeedleId]bool) error {
+	t.LogInfo("Processing .ecj file for deleted needle IDs", map[string]interface{}{
+		"file": ecjFile,
+	})
+
+	// Get base name for the file (remove .ecj extension) for IterateEcjFile
+	baseName := strings.TrimSuffix(ecjFile, ".ecj")
+
+	deletedCount := 0
+	err := erasure_coding.IterateEcjFile(baseName, func(needleId storage_types.NeedleId) error {
+		deletedNeedles[needleId] = true
+		deletedCount++
+		return nil
+	})
 
-	file, err := os.Open(ecjFile)
 	if err != nil {
-		return fmt.Errorf("failed to open .ecj file %s: %w", ecjFile, err)
+		return fmt.Errorf("failed to iterate .ecj file %s: %w", ecjFile, err)
 	}
-	defer file.Close()
 
-	// Simple implementation: if file exists and has content, we assume some deletions
-	// Real implementation would parse the binary format to extract actual needle IDs
-	info, err := file.Stat()
-	if err == nil && info.Size() > 0 {
-		// For now, just log that we found a non-empty .ecj file
-		t.LogInfo("Found non-empty .ecj file with deletions", map[string]interface{}{
-			"file": ecjFile,
-			"size": info.Size(),
-		})
-	}
+	t.LogInfo("Successfully processed .ecj file", map[string]interface{}{
+		"file":            ecjFile,
+		"deleted_needles": deletedCount,
+	})
 
 	return nil
 }
 
 // writeMergedEcjFile writes the merged deletion information to a new .ecj file
-func (t *EcVacuumTask) writeMergedEcjFile(mergedEcjFile string, deletedNeedles map[string]bool) error {
-	// TODO: Implement proper .ecj file writing
-	// For now, create an empty file since we don't have proper parsing yet
+func (t *EcVacuumTask) writeMergedEcjFile(mergedEcjFile string, deletedNeedles map[storage_types.NeedleId]bool) error {
+	t.LogInfo("Writing merged .ecj file", map[string]interface{}{
+		"file":            mergedEcjFile,
+		"deleted_needles": len(deletedNeedles),
+	})
 
 	file, err := os.Create(mergedEcjFile)
 	if err != nil {
@@ -457,9 +462,28 @@ func (t *EcVacuumTask) writeMergedEcjFile(mergedEcjFile string, deletedNeedles m
 	}
 	defer file.Close()
 
-	t.LogInfo("Created merged .ecj file", map[string]interface{}{
+	// Write each deleted needle ID as binary data
+	writtenCount := 0
+	needleBytes := make([]byte, storage_types.NeedleIdSize)
+	for needleId := range deletedNeedles {
+		storage_types.NeedleIdToBytes(needleBytes, needleId)
+		_, err := file.Write(needleBytes)
+		if err != nil {
+			return fmt.Errorf("failed to write needle ID to .ecj file: %w", err)
+		}
+		writtenCount++
+	}
+
+	// Sync to ensure data is written to disk
+	err = file.Sync()
+	if err != nil {
+		return fmt.Errorf("failed to sync .ecj file: %w", err)
+	}
+
+	t.LogInfo("Successfully wrote merged .ecj file", map[string]interface{}{
 		"file":            mergedEcjFile,
-		"deleted_needles": len(deletedNeedles),
+		"deleted_needles": writtenCount,
+		"file_size":       writtenCount * storage_types.NeedleIdSize,
 	})
 
 	return nil
@@ -574,11 +598,13 @@ func (t *EcVacuumTask) distributeNewEcShards() error {
 
 	targetBaseFileName := filepath.Join(t.tempDir, fmt.Sprintf("%s_%d_g%d", t.collection, t.volumeID, t.targetGeneration))
 
-	// Step 1: Find one server with dedicated index folder for shared index files (.ecx, .vif, .ecj)
+	// Step 1: Find best server for shared index files (.vif, .ecj)
+	// Note: .ecx files are skipped per user guidance - they can be regenerated
 	var indexServer pb.ServerAddress
 	for serverAddr := range t.sourceNodes {
-		// For now, use the first server as index server
-		// TODO: Check if server has dedicated index folder capability
+		// Use the first server as index server
+		// Future enhancement: Query volume server capabilities to find servers with dedicated index folders
+		// This could be done via a new gRPC call or by checking server configuration
 		indexServer = serverAddr
 		break
 	}