diff --git a/src/api.cpp b/src/api.cpp
index a100239..5d86c6e 100644
--- a/src/api.cpp
+++ b/src/api.cpp
@@ -2,6 +2,7 @@
 #include <HTTPClient.h>
 #include <ArduinoJson.h>
 #include "commonFS.h"
+#include "debug.h"
 
 volatile spoolmanApiStateType spoolmanApiState = API_INIT;
 //bool spoolman_connected = false;
@@ -87,6 +88,8 @@ JsonDocument fetchSingleSpoolInfo(int spoolId) {
 }
 
 void sendToApi(void *parameter) {
+    HEAP_DEBUG_MESSAGE("sendToApi begin");
+
     spoolmanApiState = API_TRANSMITTING;
     SendToApiParams* params = (SendToApiParams*)parameter;
 
@@ -131,8 +134,8 @@ void sendToApi(void *parameter) {
             }
             
             vTaskDelay(3000 / portTICK_PERIOD_MS);
-            doc.clear();
         }
+        doc.clear();
 
     } else {
         Serial.println("Fehler beim Senden an Spoolman! HTTP Code: " + String(httpCode));
@@ -145,8 +148,9 @@ void sendToApi(void *parameter) {
 
     // Speicher freigeben
     delete params;
-    vTaskDelete(NULL);
+    HEAP_DEBUG_MESSAGE("sendToApi end");
     spoolmanApiState = API_IDLE;
+    vTaskDelete(NULL);
 }
 
 bool updateSpoolTagId(String uidString, const char* payload) {
@@ -169,6 +173,8 @@ bool updateSpoolTagId(String uidString, const char* payload) {
     Serial.print("Update Spule mit URL: ");
     Serial.println(spoolsUrl);
     
+    doc.clear();
+
     // Update Payload erstellen
     JsonDocument updateDoc;
     updateDoc["extra"]["nfc_id"] = "\""+uidString+"\"";
@@ -207,6 +213,7 @@ bool updateSpoolTagId(String uidString, const char* payload) {
 }
 
 uint8_t updateSpoolWeight(String spoolId, uint16_t weight) {
+    HEAP_DEBUG_MESSAGE("updateSpoolWeight begin");
     String spoolsUrl = spoolmanUrl + apiUrl + "/spool/" + spoolId + "/measure";
     Serial.print("Update Spule mit URL: ");
     Serial.println(spoolsUrl);
@@ -241,11 +248,14 @@ uint8_t updateSpoolWeight(String spoolId, uint16_t weight) {
     );
 
     updateDoc.clear();
+    HEAP_DEBUG_MESSAGE("updateSpoolWeight end");
 
     return 1;
 }
 
 uint8_t updateSpoolLocation(String spoolId, String location){
+    HEAP_DEBUG_MESSAGE("updateSpoolLocation begin");
+
     String spoolsUrl = spoolmanUrl + apiUrl + "/spool/" + spoolId;
     Serial.print("Update Spule mit URL: ");
     Serial.println(spoolsUrl);
@@ -281,6 +291,7 @@ uint8_t updateSpoolLocation(String spoolId, String location){
 
     updateDoc.clear();
 
+    HEAP_DEBUG_MESSAGE("updateSpoolLocation end");
     return 1;
 }
 
@@ -345,6 +356,10 @@ bool updateSpoolBambuData(String payload) {
 
     String updatePayload;
     serializeJson(updateDoc, updatePayload);
+
+    doc.clear();
+    updateDoc.clear();
+
     Serial.print("Update Payload: ");
     Serial.println(updatePayload);
 
@@ -511,6 +526,7 @@ bool checkSpoolmanExtraFields() {
                     vTaskDelay(100 / portTICK_PERIOD_MS);
                 }
             }
+            doc.clear();
         }
     }
     
@@ -557,6 +573,8 @@ bool checkSpoolmanInstance(const String& url) {
                 oledShowTopRow();
                 return strcmp(status, "healthy") == 0;
             }
+
+            doc.clear();
         }
     } else {
         Serial.println("Error contacting spoolman instance! HTTP Code: " + String(httpCode));
@@ -584,6 +602,8 @@ bool saveSpoolmanUrl(const String& url, bool octoOn, const String& octoWh, const
     octoUrl = octoWh;
     octoToken = octoTk;
 
+    doc.clear();
+
     return true;
 }
 
@@ -600,6 +620,8 @@ String loadSpoolmanUrl() {
         return doc["url"].as<String>();
     }
     Serial.println("Keine gültige Spoolman-URL gefunden.");
+
+    doc.clear();
     return "";
 }
 
diff --git a/src/main.cpp b/src/main.cpp
index 01763d4..9980cbc 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -212,14 +212,14 @@ void loop() {
   lastWeight = weight;
 
   // Wenn ein Tag mit SM id erkannte wurde und der Waage Counter anspricht an SM Senden
-  if (spoolId != "" && weigthCouterToApi > 3 && weightSend == 0 && nfcReaderState == NFC_READ_SUCCESS) {
+  if (activeSpoolId != "" && weigthCouterToApi > 3 && weightSend == 0 && nfcReaderState == NFC_READ_SUCCESS) {
     oledShowIcon("loading");
-    if (updateSpoolWeight(spoolId, weight)) 
+    if (updateSpoolWeight(activeSpoolId, weight)) 
     {
       oledShowIcon("success");
       vTaskDelay(2000 / portTICK_PERIOD_MS);
       weightSend = 1;
-      autoSetToBambuSpoolId = spoolId.toInt();
+      autoSetToBambuSpoolId = activeSpoolId.toInt();
 
       if (octoEnabled) 
       {
diff --git a/src/nfc.cpp b/src/nfc.cpp
index ea10267..47dbab4 100644
--- a/src/nfc.cpp
+++ b/src/nfc.cpp
@@ -14,7 +14,8 @@ Adafruit_PN532 nfc(PN532_IRQ, PN532_RESET);
 TaskHandle_t RfidReaderTask;
 
 JsonDocument rfidData;
-String spoolId = "";
+String activeSpoolId = "";
+String lastSpoolId = "";
 String nfcJsonData = "";
 volatile bool pauseBambuMqttTask = false;
 
@@ -64,6 +65,8 @@ void payloadToJson(uint8_t *data) {
         Serial.print("deserializeJson() failed: ");
         Serial.println(error.f_str());
       }
+
+      doc.clear();
     } else {
         Serial.println("Kein gültiger JSON-Inhalt gefunden oder fehlerhafte Formatierung.");
         //writeJsonToTag("{\"version\":\"1.0\",\"protocol\":\"NFC\",\"color_hex\":\"#FFFFFF\",\"type\":\"Example\",\"min_temp\":10,\"max_temp\":30,\"brand\":\"BrandName\"}");
@@ -221,14 +224,15 @@ bool decodeNdefAndReturnJson(const byte* encodedMessage) {
     if (doc.containsKey("sm_id") && doc["sm_id"] != "") 
     {
       Serial.println("SPOOL-ID gefunden: " + doc["sm_id"].as<String>());
-      spoolId = doc["sm_id"].as<String>();
+      activeSpoolId = doc["sm_id"].as<String>();
+      lastSpoolId = activeSpoolId;
     }
     else if(doc.containsKey("location") && doc["location"] != "")
     {
       Serial.println("Location Tag found!");
       String location = doc["location"].as<String>();
-      if(spoolId != ""){
-        updateSpoolLocation(spoolId, location);
+      if(lastSpoolId != ""){
+        updateSpoolLocation(lastSpoolId, location);
       }
       else
       {
@@ -240,12 +244,14 @@ bool decodeNdefAndReturnJson(const byte* encodedMessage) {
     else 
     {
       Serial.println("Keine SPOOL-ID gefunden.");
-      spoolId = "";
+      activeSpoolId = "";
       oledShowMessage("Unknown Spool");
       vTaskDelay(2000 / portTICK_PERIOD_MS);
     }
   }
 
+  doc.clear();
+
   return true;
 }
 
@@ -446,6 +452,7 @@ void scanRfidTask(void * parameter) {
         nfcReaderState = NFC_IDLE;
         //uidString = "";
         nfcJsonData = "";
+        activeSpoolId = "";
         Serial.println("Tag entfernt");
         if (!autoSendToBambu) oledShowWeight(weight);
       }
diff --git a/src/nfc.h b/src/nfc.h
index 0d964f2..8f8cf5a 100644
--- a/src/nfc.h
+++ b/src/nfc.h
@@ -19,7 +19,8 @@ void startWriteJsonToTag(const char* payload);
 
 extern TaskHandle_t RfidReaderTask;
 extern String nfcJsonData;
-extern String spoolId;
+extern String activeSpoolId;
+extern String lastSpoolId;
 extern volatile nfcReaderStateType nfcReaderState;
 extern volatile bool pauseBambuMqttTask;