--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/minfo/BedHeightsDatacagePanel.java	Thu Jan 18 18:26:30 2018 +0100
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/minfo/BedHeightsDatacagePanel.java	Thu Jan 18 18:32:30 2018 +0100
@@ -8,83 +8,51 @@
 
 package org.dive4elements.river.client.client.ui.minfo;
 
+import java.util.List;
+
+import org.dive4elements.river.client.client.ui.AbstractPairRecommendationPanel;
+import org.dive4elements.river.client.client.ui.DatacageWidget;
+import org.dive4elements.river.client.client.ui.DefaultDatacageTwinPanelInfo;
+import org.dive4elements.river.client.client.ui.RecommendationPairRecord;
+import org.dive4elements.river.client.client.ui.WaterlevelTwinPanelValidator;
+import org.dive4elements.river.client.shared.model.DataList;
+import org.dive4elements.river.client.shared.model.ToLoad;
+import org.dive4elements.river.client.shared.model.User;
+
 import com.google.gwt.core.client.GWT;
-
 import com.smartgwt.client.util.SC;
 import com.smartgwt.client.widgets.Button;
 import com.smartgwt.client.widgets.Canvas;
-
 import com.smartgwt.client.widgets.events.ClickEvent;
 import com.smartgwt.client.widgets.events.ClickHandler;
-
+import com.smartgwt.client.widgets.grid.ListGrid;
 import com.smartgwt.client.widgets.layout.VLayout;
 import com.smartgwt.client.widgets.tree.TreeNode;
 
-import org.dive4elements.river.client.client.FLYSConstants;
-
-import org.dive4elements.river.client.client.services.LoadArtifactServiceAsync;
-import org.dive4elements.river.client.client.services.RemoveArtifactServiceAsync;
-
-import org.dive4elements.river.client.client.ui.DatacageTwinPanel;
-import org.dive4elements.river.client.client.ui.DatacageWidget;
-import org.dive4elements.river.client.client.ui.RecommendationPairRecord;
-
-import org.dive4elements.river.client.shared.model.DataList;
-import org.dive4elements.river.client.shared.model.ToLoad;
-
-import org.dive4elements.river.client.shared.model.Recommendation;
-import org.dive4elements.river.client.shared.model.User;
-
-import java.util.ArrayList;
-import java.util.List;
-
-// TODO Probably better to branch off AbstractUIProvider.
 public class BedHeightsDatacagePanel
-extends      DatacageTwinPanel {
-
-    protected static FLYSConstants MSG = GWT.create(FLYSConstants.class);
-
-    /**
-     * List to track previously selected but now removed pairs. (Needed to
-     * be able to identify artifacts that can be removed from the collection.
-     */
-    protected List<RecommendationPairRecord> removedPairs =
-        new ArrayList<RecommendationPairRecord>();
-
-    /** Service handle to clone and add artifacts to collection. */
-    LoadArtifactServiceAsync loadArtifactService = GWT.create(
-            org.dive4elements.river.client.client.services.LoadArtifactService.class);
-
-    /** Service to remove artifacts from collection. */
-    RemoveArtifactServiceAsync removeArtifactService = GWT.create(
-            org.dive4elements.river.client.client.services.RemoveArtifactService.class);
-
-    protected DatacageWidget datacage;
+extends      AbstractPairRecommendationPanel {
 
     public BedHeightsDatacagePanel(User user) {
-        super(user);
+    	// FIXME: This will lead to a bad error message in English (i.e. contains something about waterlevels), for M-Info/Bed-Differences calculation
+    	// BUT: this is the behavior of 3.2.1 (because of sloppy derivation), so we do not change it now
+        super(user, new WaterlevelTwinPanelValidator(), new DefaultDatacageTwinPanelInfo("bedheight", null), new DefaultDatacageTwinPanelInfo("bedheight", null) );
     }
 
-    /**
-     * Creates the graphical representation and interaction widgets for the data.
-     * @param dataList the data.
-     * @return graphical representation and interaction widgets for data.
-     */
     @Override
-    public Canvas create(DataList dataList) {
+    protected Canvas createChooserWidgets(final Canvas widget, final DataList dataList, final User user, final ListGrid differencesList) {
         GWT.log("createData()");
 
-        Canvas widget = createWidget();
         Canvas submit = getNextButton();
-        datacage = new DatacageWidget(
+
+        final DatacageWidget datacage = new DatacageWidget(
             this.artifact, user, "minfo_diff_panel", "load-system:true", false);
 
-        Button plusBtn = new Button(MSG.datacage_add_pair());
+        Button plusBtn = new Button(msg().datacage_add_pair());
         plusBtn.setAutoFit(true);
         plusBtn.addClickHandler(new ClickHandler() {
             @Override
             public void onClick(ClickEvent event) {
-                plusClicked();
+                plusClicked(datacage, differencesList);
             }
         });
 
@@ -98,29 +66,19 @@
         layout.setMembersMargin(10);
         this.helperContainer.addMember(helperLayout);
 
-        populateGrid(dataList, "bedheight");
-
         return layout;
     }
 
-    public void adjustRecommendation(Recommendation recommendation) {
-        recommendation.setFactory("bedheight");
-    }
-
-    @Override
-    protected String createDataString(String artifact, Recommendation recommendation) {
-        return createDataString(artifact, recommendation, "bedheight");
-    }
-
     /**
      * Callback for add-button.
      * Fires to load for every selected element and handler.
+     * @param differencesList 
      */
-    public void plusClicked() {
+    protected final static void plusClicked( final DatacageWidget datacage, ListGrid differencesList ) {
         List<TreeNode> selection = datacage.getPlainSelection();
 
         if (selection == null || selection.isEmpty()) {
-            SC.say(MSG.warning());
+            SC.say(msg().warning());
             return;
         }