Keep transitions predictable
Turning a bright aquarium light on suddenly can startle animals that were resting in darkness. Ambient room light before the tank light can soften the transition.
A timer can provide a consistent daily schedule. Keep the photoperiod suited to plants and avoid extending it simply to see shrimp longer.
Watch the response
If shrimp dart or hide after lighting changes, reduce intensity or adjust the schedule gradually. Check for other simultaneous changes before blaming light alone.
A lighting adjustment should not involve a full rescape or major water change on the same day. Make one change and observe the colony.
For your own tank
Observe whether shrimp settle after the light is dimmed or the transition is softened. Keep the day length steady and avoid changing intensity, fertilizer, and water chemistry at the same time. A quiet routine makes behavior easier to interpret.
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.