Understand visibility limits
Shrimp may be under leaves, inside moss, behind wood, or near the filter. A front-glass scan rarely shows the entire colony.
Feeding gatherings can change quickly and should not be used as a total population count.
Use repeat observations
Choose a fixed viewing time and note the number visible in a known area. Keep the estimate method consistent across observations.
Record a range or qualitative trend when the view is incomplete. Avoid inventing a percentage of hidden shrimp.
Plan conservatively
Use water quality and maintenance demands to judge whether the tank can support future growth. A colony can reproduce beyond the original purchase group.
If you need a precise count for a transfer, use a planned low-stress method and accept that tiny animals may still be missed.
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.