How would you adjust the pH of solid media?

To adjust the pH of solid media, you can incorporate acidic or alkaline substances directly into the media before sterilization. Commonly used agents include hydrochloric acid (HCl) for lowering pH or sodium hydroxide (NaOH) for raising it. It's important to dissolve these agents in a small volume of water and then mix them thoroughly with the media to ensure even distribution. Always check the pH using a calibrated pH meter after preparation and before use.