In most cases, either phosphoric acid or potassium hydroxide is used to adjust pH level of the hydroponic nutrient solution. The first substance is used to lower pH level, and the latter, consequently, is used to raise it. Being relatively safe and usually sold diluted, both of these chemicals should be handled with care, avoiding direct contact with skin or eyes. When you choose to use concentrated pH adjusters, be very accurate, because significant pH changes may lead to devastating effects on your garden.

Along with the above mentioned chemicals, there are also some other pH adjusters for hydroponic nutrient solutions. For example, nitric acid and sulfuric acid can be used to lower pH level, however, being much more dangerous chemicals, these should be handled with extreme care. Besides, some gardeners even use citric acid to lower pH level in hydroponics system.

Before checking and adjusting pH level of the nutrient solution, always do this after you added all the nutrients and fertilizers to the water, since they can influence the pH level of the solution. Check the pH level with any method you like after adding nutrients and mixing the solution. If necessary, add pH adjuster to the solution, but use only small amounts of adjuster not to raise or lower pH level too much. It is better to achieve target pH level bit by bit by adding small amounts of the adjuster and checking pH level repeatedly.

As the growing plants consume nutrients, pH level of the nutrient solution will raise. That is why it is necessary to perform regular checks of pH level and adjust it if necessary. Keep in mind that pH levels may change differently in different hydroponic systems, depending on various factors, such as type of plants, their stage of growing, environmental conditions,