diff --git a/Graph/DirectedGraph.cs b/Graph/DirectedGraph.cs
index 58a1085..72e2d0c 100644
--- a/Graph/DirectedGraph.cs
+++ b/Graph/DirectedGraph.cs
@@ -20,6 +20,25 @@ namespace MoonTools.Core.Graph
             }
         }
 
+        public virtual void AddEdge(TNode v, TNode u, TEdgeData edgeData)
+        {
+            CheckNodes(v, u);
+
+            if (v.Equals(u)) { throw new ArgumentException("Self-edges are not allowed in a simple graph. Use a multigraph instead"); }
+
+            neighbors[v].Add(u);
+            edges.Add((v, u));
+            edgeToEdgeData.Add((v, u), edgeData);
+        }
+
+        public virtual void AddEdges(params (TNode, TNode, TEdgeData)[] edges)
+        {
+            foreach (var edge in edges)
+            {
+                AddEdge(edge.Item1, edge.Item2, edge.Item3);
+            }
+        }
+
         public void RemoveNode(TNode node)
         {
             CheckNodes(node);
@@ -45,25 +64,6 @@ namespace MoonTools.Core.Graph
             neighbors.Remove(node);
         }
 
-        public virtual void AddEdge(TNode v, TNode u, TEdgeData edgeData)
-        {
-            CheckNodes(v, u);
-
-            if (v.Equals(u)) { throw new ArgumentException("Self-edges are not allowed in a simple graph. Use a multigraph instead"); }
-
-            neighbors[v].Add(u);
-            edges.Add((v, u));
-            edgeToEdgeData.Add((v, u), edgeData);
-        }
-
-        public virtual void AddEdges(params (TNode, TNode, TEdgeData)[] edges)
-        {
-            foreach (var edge in edges)
-            {
-                AddEdge(edge.Item1, edge.Item2, edge.Item3);
-            }
-        }
-
         public virtual void RemoveEdge(TNode v, TNode u)
         {
             CheckEdge(v, u);
@@ -469,12 +469,9 @@ namespace MoonTools.Core.Graph
             return subGraph;
         }
 
-        public virtual void Clear()
+        public override void Clear()
         {
-            nodes.Clear();
-            neighbors.Clear();
-            edges.Clear();
-            edgeToEdgeData.Clear();
+            base.Clear();
         }
     }
 }
diff --git a/Graph/DirectedWeightedGraph.cs b/Graph/DirectedWeightedGraph.cs
index d592f94..b88ba4c 100644
--- a/Graph/DirectedWeightedGraph.cs
+++ b/Graph/DirectedWeightedGraph.cs
@@ -6,17 +6,24 @@ using MoreLinq;
 
 namespace MoonTools.Core.Graph
 {
-    public class DirectedWeightedGraph<TNode, TEdgeData> : DirectedGraph<TNode, TEdgeData> where TNode : System.IEquatable<TNode>
+    public class DirectedWeightedGraph<TNode, TEdgeData> : SimpleGraph<TNode, TEdgeData> where TNode : System.IEquatable<TNode>
     {
         protected Dictionary<(TNode, TNode), int> weights = new Dictionary<(TNode, TNode), int>();
 
-        public void AddEdge(TNode v, TNode u, int weight, TEdgeData data)
+        public void AddEdge(TNode v, TNode u, int weight, TEdgeData edgeData)
         {
-            base.AddEdge(v, u, data);
+            CheckNodes(v, u);
+
+            if (v.Equals(u)) { throw new ArgumentException("Self-edges are not allowed in a simple graph. Use a multigraph instead"); }
+
+            neighbors[v].Add(u);
+            edges.Add((v, u));
+            edgeToEdgeData.Add((v, u), edgeData);
+
             weights.Add((v, u), weight);
         }
 
-        public void AddEdges(params (TNode, TNode, int, TEdgeData)[] edges)
+        public void AddEdges(params (TNode, TNode, int weight, TEdgeData)[] edges)
         {
             foreach (var edge in edges)
             {
diff --git a/Graph/Graph.cs b/Graph/Graph.cs
index 0423230..8e7be07 100644
--- a/Graph/Graph.cs
+++ b/Graph/Graph.cs
@@ -1,11 +1,12 @@
 using System.Collections.Generic;
+using Collections.Pooled;
 
 namespace MoonTools.Core.Graph
 {
     abstract public class Graph<TNode, TEdgeData> where TNode : System.IEquatable<TNode>
     {
         protected HashSet<TNode> nodes = new HashSet<TNode>();
-        protected Dictionary<TNode, HashSet<TNode>> neighbors = new Dictionary<TNode, HashSet<TNode>>();
+        protected Dictionary<TNode, PooledSet<TNode>> neighbors = new Dictionary<TNode, PooledSet<TNode>>();
 
         public IEnumerable<TNode> Nodes => nodes;
 
@@ -16,7 +17,7 @@ namespace MoonTools.Core.Graph
             if (!Exists(node))
             {
                 nodes.Add(node);
-                neighbors.Add(node, new HashSet<TNode>());
+                neighbors.Add(node, new PooledSet<TNode>(ClearMode.Always));
             }
         }
 
@@ -56,5 +57,10 @@ namespace MoonTools.Core.Graph
             }
         }
 
+        public virtual void Clear()
+        {
+            nodes.Clear();
+            neighbors.Clear();
+        }
     }
 }
\ No newline at end of file
diff --git a/Graph/SimpleGraph.cs b/Graph/SimpleGraph.cs
index 062d891..2e9c6c7 100644
--- a/Graph/SimpleGraph.cs
+++ b/Graph/SimpleGraph.cs
@@ -29,5 +29,12 @@ namespace MoonTools.Core.Graph
             CheckNodes(v, u);
             if (!Exists(v, u)) { throw new ArgumentException($"Edge between vertex {v} and vertex {u} does not exist in the graph"); }
         }
+
+        public override void Clear()
+        {
+            base.Clear();
+            edges.Clear();
+            edgeToEdgeData.Clear();
+        }
     }
 }
\ No newline at end of file