[Grantbowen]

We had a new walk-in shower installed about three years ago.
Since then we have noticed black spotting in the bottom corners and edge where the walls meet the floor.
No cleanser has helped to remove them.
I believe these areas were sealed with silicone.
We are concerned that it is black mold under the silicone.

What can we do

 

[joecaption]

Start by removing all the old silicone, new will not stick to old.
Wipe down the whole area with bleach and water, let dry, tape anyplace you do not want the caulking then reapply making sure it's not gooped up making areas for water to sit.
There is 0 need to have the caulking all over anything but the gap.
I remove the tape before the caulking is dry and always wear disposable gloves when doing this for faster clean up.

 

[Grantbowen]

What mix of water and bleach?