Is it safe to brush my teeth with hotel tap water? Or should I use bottled?

This depends on your stomach's sensitivity, but the general rule for tourists is: Play it safe.

The Risk: Sri Lankan tap water is chlorinated, but the pipes in older hotels can introduce bacteria. Swallowing even a small amount of foam can upset a sensitive "western" stomach.

The "Bottle" Rule: Use bottled water for brushing. Keep a bottle on the sink as a visual reminder.

The "Rumble": If you already have a rumble, switch to bottled water immediately and drink a King Coconut (Thambili), it’s the best natural electrolyte cure for a mild upset stomach.

Exceptions: In high-end 5-star hotels (like Shangri-La or Cinnamon Grand), the water is highly filtered and usually safe for brushing, but why risk it?