diff --git a/OpenPNM/Network/tools.py b/OpenPNM/Network/tools.py
index <HASH>..<HASH> 100644
--- a/OpenPNM/Network/tools.py
+++ b/OpenPNM/Network/tools.py
@@ -794,6 +794,9 @@ def find_surface_pores(network, markers=None, label='surface'):
     This function does not check whether the given markers actually lie outside
     the domain, allowing the labeling of *internal* sufaces.
 
+    If this method fails to mark some surface pores, consider sending more
+    markers on each face.
+
     Examples
     --------
     >>> import OpenPNM as op
Added more explanation to find_surface_pores to help when not all pores are identified