PH Up is classed as Dangerous Goods: In order to meet freight compliance please order full carton quantities as shown below: PH Up 250ml: 24 per carton PH Up 1 Litre: 12 per carton PH Up 5 Litre: 2 per carton All freight orders including Dangerous Goods will be adjusted to full carton quantities. HY-GEN® pH UP contains a 45% solution of potassium hydroxide, which can be added to your growing system to RAISE the pH. It’s recommended to make up your nutrient solution first and allow it to equilibrate. This can take up to 60 minutes depending on the size of your tank. Always add the required amount of pH UP to a small separate container of water and mix well before adding to your nutrient tank.