diff --git a/src/scripts/cluster.py b/src/scripts/cluster.py
index 6788abe5..2bf93ecc 100755
--- a/src/scripts/cluster.py
+++ b/src/scripts/cluster.py
@@ -178,7 +178,8 @@ def run_clustering (graph_gfa, mashmap_sim, hic_byread, output_dir, no_rdna, une
     MAX_COV = 100  # tempora# ry coverage cutoff, currently replaced by median coverage from gfa
     FIXED_WEIGHT = 100000  # best result so far with 100000 #currently replaced with max pairwise weight among datasets
 
-
+    MAX_RDNA_COMPONENT = 10000000 # maximal size of rDNA component, used for filtering out rDNA cluster only
+    MIN_RDNA_COMPONENT = 500000 
     # load the assembly gfa
     G = nx.Graph()
     logging_f = open (os.path.join(output_dir, LOGGING_FILENAME), 'w')
@@ -202,9 +203,9 @@ def run_clustering (graph_gfa, mashmap_sim, hic_byread, output_dir, no_rdna, une
 
     if not (no_rdna):
         #Store rDNA component, not to add additional links from matchGraph
-        sys.stderr.write(f"Found an rDNA huge component of {len(largest_component)} edges\n")
+        #sys.stderr.write(f"Found an rDNA huge component of {len(largest_component)} edges\n")
         #Here we remove large connected components of short edge, just to exclude rDNA cluster
-        delete_set = graph_functions.remove_large_tangles(G, MAX_SHORT_LEN, MAX_SHORT_COMPONENT)
+        delete_set = graph_functions.remove_large_tangles(G, MAX_SHORT_LEN, MAX_SHORT_COMPONENT,MIN_RDNA_COMPONENT, MAX_RDNA_COMPONENT)
     else:
         sys.stderr.write(f"Not using rDNA component removal heuristics\n")
     filtered_graph = open(os.path.join(output_dir, FILTERED_GFA_FILENAME), 'w')
diff --git a/src/scripts/graph_functions.py b/src/scripts/graph_functions.py
index 8380ce68..ce5b4d37 100755
--- a/src/scripts/graph_functions.py
+++ b/src/scripts/graph_functions.py
@@ -1,8 +1,17 @@
 import networkx as nx
 import sys
 
+
+def get_component_length(G, component):
+    res = 0
+    for node in component:
+        res += G.nodes[node]['length']
+    return res
+
 #Functions for indirect graph processing, nodes - "utig1-234"
-def remove_large_tangles(G, MAX_LEN, MAX_SHORT_COMPONENT):
+
+#TODO: here should be a better check, with either rDNA nodes or diploid structure. After scaff refactor
+def remove_large_tangles(G, MAX_LEN, MAX_SHORT_COMPONENT, MIN_RDNA_COMPONENT, MAX_RDNA_COMPONENT):
     shorts = set()
     for node in G.nodes():
         if G.nodes[node]['length'] < MAX_LEN:
@@ -11,12 +20,36 @@ def remove_large_tangles(G, MAX_LEN, MAX_SHORT_COMPONENT):
     nodes_deleted = 0
     components_deleted = 0
     to_delete = []
-    for comp in nx.connected_components(sh_G):
+    #largest tangle will be always removed (unless --no-rdna-tangle used which completely disable tangle removal heuristics)
+    First = True
+
+    for comp in sorted(nx.connected_components(sh_G), key=len, reverse=True):
         if len(comp) > MAX_SHORT_COMPONENT:
-            components_deleted += 1
-            for e in comp:
-                nodes_deleted += 1
-                to_delete.append(e)
+#lets check whether component looks similar to rdna 
+            first_edge = list(comp)[0]
+            sys.stderr.write(f'Checking component with first edge {first_edge}\n')
+            first_edge_big_comp = nx.node_connected_component(G, first_edge)
+            not_deleting = set( )
+            for e in first_edge_big_comp:
+                if not e in comp:
+                    not_deleting.add(e)
+            subgraph_comp = G.subgraph(not_deleting)
+            new_connected = nx.connected_components(subgraph_comp)
+            good_new_connected = False
+            for new_comp in new_connected:
+                tlen = get_component_length(G, new_comp)
+                if tlen < MAX_RDNA_COMPONENT and tlen > MIN_RDNA_COMPONENT:
+                    good_new_connected = True                     
+                    sys.stderr.write(f'Component  size {tlen}, small enough\n')               
+                    break
+            if First or good_new_connected:
+                First = False                   
+                components_deleted += 1
+                for e in comp:
+                    nodes_deleted += 1
+                    to_delete.append(e)
+            else:
+                sys.stderr.write(f'Not deleting component {comp}, nothing similar to rDNA\n')
     G.remove_nodes_from(to_delete)
     sys.stderr.write(f'Removed {components_deleted} short nodes components and {nodes_deleted} short nodes. New '
                      f'number of nodes {G.number_of_nodes()}\n')