diff --git a/app/models/request_for_comment.rb b/app/models/request_for_comment.rb
index d0c300b6..e46f3048 100644
--- a/app/models/request_for_comment.rb
+++ b/app/models/request_for_comment.rb
@@ -8,6 +8,7 @@ class RequestForComment < ActiveRecord::Base
   has_many :subscriptions
 
   scope :unsolved, -> { where(solved: [false, nil]) }
+  scope :not_stale, -> { where("user_id%10 <2 OR user_id%10 >= 4").where(exercise.exercise_collections.none{|ec| ec.id = 3} } ########### todo
 
     def self.last_per_user(n = 5)
       from("(#{row_number_user_sql}) as request_for_comments").where("row_number <= ?", n)
diff --git a/app/models/submission.rb b/app/models/submission.rb
index c27d01bd..496ae056 100644
--- a/app/models/submission.rb
+++ b/app/models/submission.rb
@@ -66,6 +66,6 @@ class Submission < ActiveRecord::Base
   end
 
   def unsolved_rfc
-    RequestForComment.unsolved.where(exercise_id: exercise).where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < MAX_COMMENTS_ON_RECOMMENDED_RFC) }
+    RequestForComment.unsolved.not_stale.where(exercise_id: exercise).where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < MAX_COMMENTS_ON_RECOMMENDED_RFC) }
   end
 end