Changing or rearranging tank decor is important for your turtle's mental and physical stimulation. However, it's essential to strike a balance and not disrupt your turtle's sense of security too frequently. As a general guideline, consider changing or rearranging the decor every few months. This helps prevent boredom and encourages exploration. However, it's essential to monitor your turtle's behavior after making changes. If your turtle appears stressed or exhibits signs of distress, such as refusing to eat or hiding excessively, it may be a sign that the change was too drastic. In such cases, return the tank decor to its original setup or make adjustments to create a more comfortable environment for your turtle.