black water tank -- I see toilet paper

It sounds like you might have a pyramid problem which could turn into one later down the road. when I flush my tank I fill the Black tank to full then flush, I will do this 3 to 4 times untill the tank flush water is flowing without any occaisional waist showing. another thing you can try is go to Home depot and purchase a box of Rid X septic tank cleaner put that in the tank fill it up let it sit for 24 hours it will clean the tank squeaky clean. flush it a couple of times then you should be good to go.