Index: sources/gui/qml/globals/Variables.qml
===================================================================
diff -u -r53ec19e12772f2a73190323438106dc93e4a12df -r7d2122a9a4330ebc2ff4c22be36f32e9a82417ec
--- sources/gui/qml/globals/Variables.qml	(.../Variables.qml)	(revision 53ec19e12772f2a73190323438106dc93e4a12df)
+++ sources/gui/qml/globals/Variables.qml	(.../Variables.qml)	(revision 7d2122a9a4330ebc2ff4c22be36f32e9a82417ec)
@@ -221,9 +221,17 @@
 
     // Potassium
     readonly property int  potassiumPrecision       : 1
+    readonly property int  potassiumMin             : 0
+    readonly property int  potassiumMax             : 4
+    readonly property int  potassiumResolution      : 1
+    readonly property int  potassiumDefault         : 2
 
     // Calcium
-    readonly property int  calciumPrecision         : 2
+    readonly property int   calciumPrecision        : 2
+    readonly property real  calciumMin              : 0.0
+    readonly property real  calciumMax              : 3.5
+    readonly property real  calciumResolution       : 0.25
+    readonly property real  calciumDefault          : 2.5
 
     function sizeConverted(vSize, vSizePowers, vRound = 2) {
         return (  vSize