Black tank won't drain...

bobphoenix wrote:
Dang!!! After reading all the replys here and knowing what I want an answer to... I almost saw what I was looking for when Mister_D said

The key to the whole thing is to have the right amount of liquid in the tank....

So, here's my question... How much water is enough...?
After I dump the black tank, I usually fill and empty the toilet bowl four times to "charge" the tank then toss in a packet of tank fresh...

I figure the bowl holds about two gallons, so that's about eight gallons in the bottom... the trouble is I don't know how many gallons my tank is...