diff --git a/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java b/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
index 3d5950d1..dbe04ac8 100644
--- a/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
+++ b/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
@@ -26,8 +26,12 @@ import android.support.v4.app.Fragment;
 import android.util.Log;
 import android.widget.Toast;
 
+import com.health.openscale.R;
 import com.health.openscale.core.alarm.AlarmHandler;
 import com.health.openscale.core.bluetooth.BluetoothCommunication;
+import com.health.openscale.core.bodymetric.EstimatedFatMetric;
+import com.health.openscale.core.bodymetric.EstimatedLBWMetric;
+import com.health.openscale.core.bodymetric.EstimatedWaterMetric;
 import com.health.openscale.core.database.AppDatabase;
 import com.health.openscale.core.database.ScaleDatabase;
 import com.health.openscale.core.database.ScaleMeasurementDAO;
@@ -60,7 +64,7 @@ public class OpenScale {
     private ScaleUserDAO userDAO;
     private ScaleDatabase scaleDB;
     private ScaleUserDatabase scaleUserDB;
-    private ArrayList<ScaleData> scaleDataList;
+    private List<ScaleData> scaleDataList;
 
     private BluetoothCommunication btCom;
     private String btDeviceName;
@@ -144,7 +148,7 @@ public class OpenScale {
         userDAO.update(user);
     }
 
-    public ArrayList<ScaleData> getScaleDataList() {
+    public List<ScaleData> getScaleDataList() {
         return scaleDataList;
     }
 
@@ -155,35 +159,13 @@ public class OpenScale {
     }
 
     public int addScaleData(final ScaleData scaleData) {
-
-        AsyncTask.execute(new Runnable() {
-            @Override
-            public void run() {
-                Log.d("TEST", "ADD START");
-
-                measurementDAO.insert(scaleData);
-
-                Log.d("TEST", "ADD END");
-
-                Log.d("TEST", "READ ALL");
-
-                List<ScaleData> listScaleData = measurementDAO.getAll();
-
-                for(ScaleData nextScaleData : listScaleData) {
-                    Log.d("TEST", "DB : " + nextScaleData.getDateTime() + " Weight: " + nextScaleData.getWeight());
-                }
-            }
-        });
-
-
-        return -1;
-/*        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
 
         if (scaleData.getUserId() == -1) {
             if (prefs.getBoolean("smartUserAssign", false)) {
                 scaleData.setUserId(getSmartUserAssignment(scaleData.getWeight(), 15.0f));
             } else {
-                scaleData.setUserId(getSelectedScaleUser().id);
+                scaleData.setUserId(getSelectedScaleUser().getId());
             }
 
             // don't add scale data if no user is selected
@@ -210,16 +192,17 @@ public class OpenScale {
             scaleData.setFat(fatMetric.getFat(getScaleUser(scaleData.getUserId()), scaleData));
         }
 
-        if (scaleDB.insertEntry(scaleData)) {
+        if (measurementDAO.get(scaleData.getDateTime(), scaleData.getUserId()) == null) {
+            measurementDAO.insert(scaleData);
             ScaleUser scaleUser = getScaleUser(scaleData.getUserId());
 
-            String infoText = String.format(context.getString(R.string.info_new_data_added), scaleData.getConvertedWeight(scaleUser.scaleUnit), scaleUser.UNIT_STRING[scaleUser.scaleUnit], dateTimeFormat.format(scaleData.getDateTime()), scaleUser.userName);
+            String infoText = String.format(context.getString(R.string.info_new_data_added), scaleData.getConvertedWeight(scaleUser.getScaleUnit()), scaleUser.UNIT_STRING[scaleUser.getScaleUnit()], dateTimeFormat.format(scaleData.getDateTime()), scaleUser.getUserName());
             Toast.makeText(context, infoText, Toast.LENGTH_LONG).show();
             alarmHandler.entryChanged(context, scaleData);
             updateScaleData();
         }
 
-        return scaleData.getUserId();*/
+        return scaleData.getUserId();
     }
 
     private int getSmartUserAssignment(float weight, float range) {
@@ -259,7 +242,7 @@ public class OpenScale {
     }
 
     public void updateScaleData(ScaleData scaleData) {
-        scaleDB.updateEntry(scaleData.getId(), scaleData);
+        measurementDAO.update(scaleData);
         alarmHandler.entryChanged(context, scaleData);
 
         updateScaleData();
@@ -305,7 +288,7 @@ public class OpenScale {
 
                 newScaleData.setUserId(getSelectedScaleUser().getId());
 
-                scaleDB.insertEntry(newScaleData);
+                measurementDAO.insert(newScaleData);
 
                 line = csvReader.readLine();
             }
@@ -414,7 +397,7 @@ public class OpenScale {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         int selectedUserId  = prefs.getInt("selectedUserId", -1);
 
-        scaleDataList = scaleDB.getScaleDataList(selectedUserId);
+        scaleDataList = measurementDAO.getAll(selectedUserId);
 
         fragment.updateOnView(scaleDataList);
     }
@@ -424,7 +407,7 @@ public class OpenScale {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         int selectedUserId  = prefs.getInt("selectedUserId", -1);
 
-        scaleDataList = scaleDB.getScaleDataList(selectedUserId);
+        scaleDataList = measurementDAO.getAll(selectedUserId);
 
         for (FragmentUpdateListener fragment : fragmentList) {
             if (fragment != null) {
diff --git a/android_app/app/src/main/java/com/health/openscale/core/database/ScaleMeasurementDAO.java b/android_app/app/src/main/java/com/health/openscale/core/database/ScaleMeasurementDAO.java
index 0850afe8..0fde1780 100644
--- a/android_app/app/src/main/java/com/health/openscale/core/database/ScaleMeasurementDAO.java
+++ b/android_app/app/src/main/java/com/health/openscale/core/database/ScaleMeasurementDAO.java
@@ -24,12 +24,16 @@ import android.arch.persistence.room.Update;
 
 import com.health.openscale.core.datatypes.ScaleData;
 
+import java.util.Date;
 import java.util.List;
 
 @Dao
 public interface ScaleMeasurementDAO {
-    @Query("SELECT * FROM scaledata")
-    List<ScaleData> getAll();
+    @Query("SELECT * FROM scaledata WHERE datetime = :datetime AND userId = :userId")
+    ScaleData get(Date datetime, int userId);
+
+    @Query("SELECT * FROM scaledata WHERE userId = :userId")
+    List<ScaleData> getAll(int userId);
 
     @Query("SELECT * FROM scaledata WHERE id IS :id")
     ScaleData loadById(int id);
diff --git a/android_app/app/src/main/java/com/health/openscale/core/database/ScaleUserDAO.java b/android_app/app/src/main/java/com/health/openscale/core/database/ScaleUserDAO.java
index 393f8c19..1f2baa9a 100644
--- a/android_app/app/src/main/java/com/health/openscale/core/database/ScaleUserDAO.java
+++ b/android_app/app/src/main/java/com/health/openscale/core/database/ScaleUserDAO.java
@@ -31,10 +31,10 @@ public interface ScaleUserDAO {
     @Query("SELECT * FROM scaleuser")
     List<ScaleUser> getAll();
 
-    @Query("SELECT * FROM scaleuser WHERE id IS :id")
+    @Query("SELECT * FROM scaleuser WHERE id = :id")
     ScaleUser getById(int id);
 
-    @Query("SELECT * FROM scaleuser WHERE id IS :id")
+    @Query("SELECT * FROM scaleuser WHERE id = :id")
     ScaleUser loadById(int id);
 
     @Insert
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/fragments/FragmentUpdateListener.java b/android_app/app/src/main/java/com/health/openscale/gui/fragments/FragmentUpdateListener.java
index a93c8fd9..dcfff5e2 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/fragments/FragmentUpdateListener.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/fragments/FragmentUpdateListener.java
@@ -18,8 +18,8 @@ package com.health.openscale.gui.fragments;
 
 import com.health.openscale.core.datatypes.ScaleData;
 
-import java.util.ArrayList;
+import java.util.List;
 
 public interface FragmentUpdateListener {
-    public void updateOnView(ArrayList<ScaleData> scaleDataList);
+    public void updateOnView(List<ScaleData> scaleDataList);
 }
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/fragments/GraphFragment.java b/android_app/app/src/main/java/com/health/openscale/gui/fragments/GraphFragment.java
index b9f9ba32..84bd1861 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/fragments/GraphFragment.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/fragments/GraphFragment.java
@@ -186,7 +186,7 @@ public class GraphFragment extends Fragment implements FragmentUpdateListener {
     }
 
     @Override
-    public void updateOnView(ArrayList<ScaleData> scaleDataList)
+    public void updateOnView(List<ScaleData> scaleDataList)
     {
         generateGraphs();
     }
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java b/android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java
index ca76de13..354df286 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java
@@ -174,7 +174,7 @@ public class OverviewFragment extends Fragment implements FragmentUpdateListener
     }
 
     @Override
-    public void updateOnView(ArrayList<ScaleData> scaleDataList) {
+    public void updateOnView(List<ScaleData> scaleDataList) {
         if (scaleDataList.isEmpty()) {
             lastScaleData = new ScaleData();
         } else if (userSelectedData != null) {
@@ -237,7 +237,7 @@ public class OverviewFragment extends Fragment implements FragmentUpdateListener
     }
 
 
-    private void updateLastLineChart(ArrayList<ScaleData> scaleDataList) {
+    private void updateLastLineChart(List<ScaleData> scaleDataList) {
         List<AxisValue> axisValues = new ArrayList<AxisValue>();
 
         List<PointValue> valuesWeight = new ArrayList<PointValue>();
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/fragments/StatisticsFragment.java b/android_app/app/src/main/java/com/health/openscale/gui/fragments/StatisticsFragment.java
index 202c810e..8985fc40 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/fragments/StatisticsFragment.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/fragments/StatisticsFragment.java
@@ -33,8 +33,8 @@ import com.health.openscale.core.datatypes.ScaleUser;
 import com.health.openscale.core.utils.DateTimeHelpers;
 
 import java.text.DateFormat;
-import java.util.ArrayList;
 import java.util.Calendar;
+import java.util.List;
 
 public class StatisticsFragment extends Fragment implements FragmentUpdateListener {
 
@@ -88,7 +88,7 @@ public class StatisticsFragment extends Fragment implements FragmentUpdateListen
     }
 
     @Override
-    public void updateOnView(ArrayList<ScaleData> scaleDataList) {
+    public void updateOnView(List<ScaleData> scaleDataList) {
         if (scaleDataList.isEmpty()) {
             lastScaleData = new ScaleData();
         } else {
@@ -105,7 +105,7 @@ public class StatisticsFragment extends Fragment implements FragmentUpdateListen
         updateGoal(scaleDataList);
     }
 
-    private void updateGoal(ArrayList<ScaleData> scaleDataList) {
+    private void updateGoal(List<ScaleData> scaleDataList) {
         ScaleData goalScaleData = new ScaleData();
         goalScaleData.setConvertedWeight(currentScaleUser.getGoalWeight(), currentScaleUser.getScaleUnit());
 
@@ -157,7 +157,7 @@ public class StatisticsFragment extends Fragment implements FragmentUpdateListen
         ); // currentScaleUser.goalDate
     }
 
-    private void updateStatistics(ArrayList<ScaleData> scaleDataList) {
+    private void updateStatistics(List<ScaleData> scaleDataList) {
         Calendar histDate = Calendar.getInstance();
         Calendar weekPastDate = Calendar.getInstance();
         Calendar monthPastDate = Calendar.getInstance();
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/fragments/TableFragment.java b/android_app/app/src/main/java/com/health/openscale/gui/fragments/TableFragment.java
index 29236924..e1d2905f 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/fragments/TableFragment.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/fragments/TableFragment.java
@@ -68,6 +68,7 @@ import com.health.openscale.gui.views.WeightMeasurementView;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 
 import lecho.lib.hellocharts.util.ChartUtils;
 
@@ -129,7 +130,7 @@ public class TableFragment extends Fragment implements FragmentUpdateListener {
     }
 
     @Override
-    public void updateOnView(ArrayList<ScaleData> scaleDataList)
+    public void updateOnView(List<ScaleData> scaleDataList)
     {
         tableDataView.setAdapter(new ListViewAdapter(new ArrayList<HashMap<Integer, String>>())); // delete all data in the table with an empty adapter array list