RV Repair: Leaking from top of black water tank, tioga arrow, silicone caulking

Question
Any ideas on how to stop a leak from the top of the black water tank - when it gets full?  This is on a '89 tioga Arrow   
Class C.  We have had few repairs.

Answer
There are 3 choices-
1) If the crack/hole is not too large, they make tank repair kits. These can only be used if the leak is on top of the tank.
2) If it is too large, you need to replace the tank.
3) Seal the hole (silicone caulking, gray tape) and don't fill the tank to capacity.

#1 would be the best option.
I hope this helps you,
Dave