diff --git a/config/templates/sinktest.conf b/config/templates/sinktest.conf
index 1088da3..b1e118e 100644
--- a/config/templates/sinktest.conf
+++ b/config/templates/sinktest.conf
@@ -65,6 +65,7 @@ AC_accretion_range = 0.2
 AC_unit_velocity = 1e5
 // using density estimate of 100 H2 molecules per cm^3
 AC_unit_density = 3e-22
+// using 10,000 AU 
 AC_unit_length = 1.5e17
 
 /*