There are a few methods that can help you increase the pH level of your shampoo: - Add more water to your formulation. Water typically has a pH of around 7, so be sure to test the pH of the water before adding it to the formulation, just in case you actually find that it is more acidic than it should be. Ultimately, the water will help to dilute the formulation a little, raising the pH. - Add a little more surfactant to the formulation. This will be your Coco-Glucoside or Reetha Powder. You don't want to add too much since that can quickly cause your pH to become much too high. Therefore, be careful to only add the tiniest bit at a time, testing in between - You can also try dissolving 1g of baking soda in 10mL of water. Then, add drop by drop into your shampoo and mix in-between until the pH is up to 4.5 (like for lowering the pH with lemon but the other way). - Add potassium sorbate to your formulation if you haven't already. It's a gentle preservative that will also push the pH of your shampoo higher (make sure it's not too high!)