diff --git a/View/sample_data_tab.py b/View/sample_data_tab.py
index 85cb76f..9d1467f 100644
--- a/View/sample_data_tab.py
+++ b/View/sample_data_tab.py
@@ -28,6 +28,7 @@ import pandas as pd
 import itertools
 
 import matplotlib.pyplot as plt
+# from QtCore.QByteArray import length
 from matplotlib.colors import LogNorm, BASE_COLORS
 from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
 from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolBar
@@ -189,6 +190,9 @@ class SampleDataTab(QWidget):
 
         self.combobox_x_axis = QComboBox()
         self.combobox_x_axis.addItems(['Concentration (g/L)', 'Concentration (%)'])
+        self.combobox_x_axis.setItemData(1,
+                                         "FINE : 100 * Cfine / (Cfine + Csand)  |  SAND : 100 * Csand / (Cfine + Csand)"
+                                         , Qt.ToolTipRole)
         self.gridLayout_groupbox_option_total_concentration_plot.addWidget(self.combobox_x_axis, 0, 1)
 
         self.label_y_axis = QLabel()
@@ -246,6 +250,9 @@ class SampleDataTab(QWidget):
 
         self.pushbutton_plot_transect.clicked.connect(self.fill_comboboxes_and_plot_transect)
 
+        self.combobox_x_axis.currentIndexChanged.connect(self.plot_total_concentration)
+        self.combobox_y_axis.currentIndexChanged.connect(self.plot_total_concentration)
+
         self.combobox_PSD_plot.currentTextChanged.connect(self.plot_PSD_fine_and_sand_sediments)
 
     # -------------------- Functions for Sample Data Tab --------------------
@@ -424,6 +431,8 @@ class SampleDataTab(QWidget):
                     i, 0, self.comboBox_sample_table_fine[i]
                 )
 
+                self.comboBox_sample_table_fine[i].setCurrentIndex(i % len(list(color_list.keys())))
+
                 self.comboBox_sample_table_fine[i]\
                     .currentTextChanged\
                     .connect(self.plot_total_concentration)
@@ -469,8 +478,8 @@ class SampleDataTab(QWidget):
             self.tableWidget_fine.itemChanged.connect(self.plot_total_concentration)
             self.tableWidget_fine.itemChanged.connect(self.plot_PSD_fine_and_sand_sediments)
 
-            self.combobox_x_axis.currentIndexChanged.connect(self.plot_total_concentration)
-            self.combobox_y_axis.currentIndexChanged.connect(self.plot_total_concentration)
+            # self.combobox_x_axis.currentIndexChanged.connect(self.plot_total_concentration)
+            # self.combobox_y_axis.currentIndexChanged.connect(self.plot_total_concentration)
 
             self.plot_sample_position_on_transect()
             self.plot_total_concentration()
@@ -521,6 +530,8 @@ class SampleDataTab(QWidget):
                     i, 0, self.comboBox_sample_table_sand[i]
                 )
 
+                self.comboBox_sample_table_sand[i].setCurrentIndex(i % len(list(color_list.keys())))
+
                 self.comboBox_sample_table_sand[i]\
                     .currentTextChanged\
                     .connect(self.plot_total_concentration)
@@ -1367,6 +1378,11 @@ class SampleDataTab(QWidget):
 
         else:
 
+            self.tableWidget_fine.blockSignals(True)
+            self.tableWidget_sand.blockSignals(True)
+            self.combobox_x_axis.blockSignals(True)
+            self.combobox_y_axis.blockSignals(True)
+
             self.verticalLayout_groupbox_plot_total_concentration.removeWidget(self.canvas_plot_total_concentration)
             self.verticalLayout_groupbox_plot_total_concentration.removeWidget(self.toolbar_plot_total_concentration)
 
@@ -1632,6 +1648,11 @@ class SampleDataTab(QWidget):
             self.axis_total_concentration.legend(loc="upper right")
             self.figure_total_concentration.canvas.draw_idle()
 
+            self.tableWidget_fine.blockSignals(False)
+            self.tableWidget_sand.blockSignals(False)
+            self.combobox_x_axis.blockSignals(False)
+            self.combobox_y_axis.blockSignals(False)
+
     def plot_PSD_fine_and_sand_sediments(self):
 
         """ Update the plot of Particle Size Distribution according to choices of x-axis and y-axis combo-boxes """