Why substrate layers matters
A new layer of sand or gravel can shift during planting and maintenance, exposing material below it. In a shrimp-focused aquarium, the choice should also support steady routines, visible livestock, and access for basic care.
Before you act, check whether the cap remains intact around plants and hardscape. Compare the item with the rest of the setup and note any recent change that could affect what you are seeing.
A careful way to proceed
plant gently and spot-clean loose debris rather than turning the whole bed. Make one adjustment at a time and watch how the aquarium responds during normal observation.
Avoid assuming a thin top layer will remain separated without monitoring. Labels, products, and tank conditions differ, so use a reliable guide as context and record what you directly observe. If uncertainty remains, ask an experienced shrimp keeper before making a consequential change.
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.