Why does a black shower head look spotless one week and chalky the next? Hard water. Minerals dry as pale marks, and on a dark finish they show far more than on chrome. Knowing that up front makes black shower heads and rails easy to live with.
The fix is a habit, not a product. After the last shower of the day, rinse the head and rail with cool water and wipe them with a soft microfibre cloth. Once a week, wash them with warm water and a little mild soap, then dry them. Skip vinegar, bleach, bathroom descalers and scourers, which can leave dull patches on a black surface. If your head has flexible rub-clean nozzles, run a thumb over them to push out scale. A squeegee on the nearby glass helps too, because the same minerals mark the screen.
The range includes rain shower heads, rail showers, hand showers on wall brackets and twin shower sets that pair an overhead head with a handset. Each product title names the finish, matte black or black, so check the title when you match pieces bought at different times. Shower heads and sets are WELS rated, and everything is sold at trade prices.