Black chunks and film in a toilet bowl?

Sounds like mold. I would spray a bleach cleaner under there and then get the kind that goes in the tank (with bleach) that will release with each flush.

Yes I have done that and the gunk still exists!!!! Thank you for your help!!!!!!

It could be from hard water like mine. I pour a few inches of vinegar in the tank and it comes clean. It is an ongoing issue. Once it is clean, maintenance is about once a month. Scrubbing does no good, nor does bleach.

There is a new product on the market to take care of that, but I used two denture tablets in mine last night, when I flushed this morning, didn't see any black flakes. I don't usually buy pop, but I bought a carton of diet pepsi, I hated it so gave it to my handyman. Had one in the fridge. Poured it in the commode and left it over night. Gads what a good job that did. no scrubbing.

I will give that a try, even though I do not have that problem in the main bathroom that has copper piping going to it!!! Thank you so much!!!

Sounds like mold to me. Put white vinegar in your tank to clean out the tank and toliet bowl. Do daily until it disappears. Then I would add one of those tank tablets to keep it clean.

The black chinks and film are caused by the presence of iron and manganese. Copper tends to neutralize the manganese. It's possible the PEX manifold and/or connectors have manganese in them. Would need to be replaced with copper or brass.