Hi all, I recently learned this on youtube regarding collectors when you are raiding and how to tell if they are full. For gold mines, if the little bucket is at the top and not going in an out of the mine you can bet the collectors are all full. For elixir you can actually see thru the clear tube what the level of elixir is and they will not be "bubbling" out any elixir from the tube. I actually just look at gold now cuz chances are if gold collectors are full then elixir is as well tho this is not always true. This is a good base to raid because you don't have to use any troops to get to inside storages if most of his money is in collectors. Hope this was helpful and good luck clan!! 
