diff --git a/ribasim_qgis/core/nodes.py b/ribasim_qgis/core/nodes.py
index 30682ba3b..9a1859c77 100644
--- a/ribasim_qgis/core/nodes.py
+++ b/ribasim_qgis/core/nodes.py
@@ -357,6 +357,64 @@ def attributes(cls) -> list[QgsField]:
         ]
 
 
+class BasinConcentrationExternal(Input):
+    @classmethod
+    def input_type(cls) -> str:
+        return "Basin / concentration_external"
+
+    @classmethod
+    def geometry_type(cls) -> str:
+        return "No Geometry"
+
+    @classmethod
+    def attributes(cls) -> list[QgsField]:
+        return [
+            QgsField("time", QVariant.DateTime),
+            QgsField("node_id", QVariant.Int),
+            QgsField("substance", QVariant.String),
+            QgsField("concentration", QVariant.Double),
+        ]
+
+
+class BasinConcentrationState(Input):
+    @classmethod
+    def input_type(cls) -> str:
+        return "Basin / concentration_state"
+
+    @classmethod
+    def geometry_type(cls) -> str:
+        return "No Geometry"
+
+    @classmethod
+    def attributes(cls) -> list[QgsField]:
+        return [
+            QgsField("time", QVariant.DateTime),
+            QgsField("node_id", QVariant.Int),
+            QgsField("substance", QVariant.String),
+            QgsField("concentration", QVariant.Double),
+        ]
+
+
+class BasinConcentration(Input):
+    @classmethod
+    def input_type(cls) -> str:
+        return "Basin / concentration"
+
+    @classmethod
+    def geometry_type(cls) -> str:
+        return "No Geometry"
+
+    @classmethod
+    def attributes(cls) -> list[QgsField]:
+        return [
+            QgsField("time", QVariant.DateTime),
+            QgsField("node_id", QVariant.Int),
+            QgsField("substance", QVariant.String),
+            QgsField("drainage", QVariant.Double),
+            QgsField("precipitation", QVariant.Double),
+        ]
+
+
 class BasinSubgridLevel(Input):
     @classmethod
     def input_type(cls) -> str: