pH Guide For Plant Cultivation

One of the most common problems in hydroponics is an unbalanced pH. When pH goes awry everything else soon follows. It is important to maintain the correct pH in the reservoir of your hydroponic system, to ensure a healthy and thriving plant.

Why is it important to have the right pH for your plants? 

The pH value directly affects the availability of most elements, especially micronutrients.
Too low pH can result in increased micronutrients availability that can lead to toxic reactions in certain plant species.
Too high pH will lock some elements that will not be available to the plants.

AR-160619984Low pH causes:
Toxin levels of iron (Fe), manganese (Mn), zinc (Mn) Zn), copper (Cu)
Lack of calcium (Ca), magnesium (Mg)
High pH causes:
Lack of iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B).

PH that is too high or too low can be harmful to the plants themselves in many other ways. The best way to handle pH adjustment is by slowly adjusting the pH of the water little by little. Let the water and nutrients stand for a while and allow it to stabilize, then test your values and adjust the pH again.

You will notice that the best pH level for nutrient absorption is around 6.5 pH. This is where most nutrients become available for your plants’ absorption.

How do I measure pH?


Beginner: Use a paper strip coated in a pH indicating dye. Dip the strip into the water and wait for the strip to change color. Then compare the color against a pH color chart to determine the corresponding pH level number.
Intermediate: Use a pH testing kit for liquids. This is a dye that you drop into the water which will change color. Again, use a pH color chart to get a reading of the pH level.
Advanced: A digital pH meter can be used to obtain the most accurate reading of the pH level. These digital meters are available at your local indoor gardening supplier like Oasis Garden Hydroponics.


It is important to always measure pH after adding nutrients to the water you are feeding your plants. Nutrients can have a large effect on pH and failing to notice the shift can be detrimental to your plants. When measuring pH, the more often the better.

How to correct pH?

Specialized pH adjusting liquids are sold in most gardening or hydroponic stores like Oasis Garden Hydroponics.  They are clearly labeled pH Up or pH Down and should be used in accordance with your needs and as directed on the bottles. Make sure to go slowly, pH is very volatile and can change quickly if too much pH adjuster is added.

Take note of what pH your plant thrives in best. Here are some examples:





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