Hydroponic gardening is a method of growing plants in water, using no soil, but using the nutrients in the water to nourish the plants. it is important to measure the pH of your hydroponic solution, as different plants survive in different pH factors.
the pH levels for hydroponic plants is not the same as soil plants.
What Is pH Level?
The pH of a solution is a measurement of the amount of free hydrogen ions.
The letters pH stand for Potential of Hydrogen, which measures the level of acidity or alkalinity of a nutrient solution.
Important: The pH scale runs from 0 to 14, anything lower than 7 is acidic, greater than 7 is alkaline, and 7 is considered a neutral pH.
The Importance of pH In Hydroponics
You could have the perfect lighting, humidity, air movement, plant spacing and balance of nutrients; but if you don’t have the right pH, your plants are gonna be unhealthy.
With plants grown in soil, pH is naturally controlled because the minerals found in the soil respond to water buffer variations and nutrient cycles.
In the hydroponic system you have to measure and maintain the pH level so you can establish an ideal environment so that the roots can absorb the nutrients that they need! Since all plants require different nutrients, all plants will require a different pH.
Keep in mind: The right pH will ensure that you’ll have high yielding healthy beautiful tasting plants and fewer pest problems. If the pH is not correct it determines availability since certain nutrients are much more effected by pH than others.
Typical pH Ranges for Crops and Nutrient Systems
Typically, the ideal pH level of crops grown hydroponically is 5.5 – 6.0. This is true for many fruits and vegetables, including parsley, tomatoes, beans, melons, and apples.
Some crops, like pumpkins, have a lower pH range of 5.5 – 7.5.
Hydroponic nutrient products generally pH levels are in the range of 5.5 – 6.0.
Again, this pH level depends on the composition of the solution. Calcium salts bring pH levels up while ammonium nitrate brings pH levels down.
It is important to know that a nutrient lockout can occur if pH levels are too high or too low.
Certain nutrients rely on specific pH levels for plant uptake.
For example: When the pH level is less than 5.0, plants could be experiencing calcium and magnesium deficiencies. Iron and calcium toxicity are also possible at pH levels less than 5.0. When pH levels reach above 6.0 or 6.5 plants may be in jeopardy of experiencing iron deficiency.
A Typical Hydroponic pH Level Chart
| Plant | pH |
|---|---|
| Basil | 5.5-6.5 |
| Bean (Common) | 6.0-6.0 |
| Bean (Broad) | 6.0-6.5 |
| Bell Peppers | 6.0-6.7 |
| Broccoli | 6.0-6.5 |
| Brussel Sprouts | 6.5-7.5 |
| Cabbage | 6.5-7.0 |
| Cauliflower | 6.0-7.0 |
| Celery | 6.3-6.7 |
| Chives | 6.0-6.5 |
| Cucumber | 5.8-6.0 |
| Eggplant | 5.5-6.5 |
| Lavender | 6.4-6.8 |
| Lemon Balm | 5.5-6.5 |
| Lettuce | 5.5-6.5 |
| Melon | 5.5-6.0 |
| Mint | 5.5-6.0 |
| Pak Choi | 7 |
| Parsley | 5.5-6.0 |
| Pea | 6.0-7.0 |
| Peas (Sugar) | 6.0-6.8 |
| Peppers (Bell) | 6.0-6.5 |
| Peppers (Hot) | 6.0-6.5 |
| Pumpkin | 5.5-7.5 |
| Sage | 5.5-6.5 |
| Spinach | 5.5-6.6 |
| Squash | 5.0-6.5 |
| Strawberries | 5.5-6.5 |
| Swiss Chard | 6.0-6.5 |
| Thyme | 5.5-7.0 |
| Tomato | 5.5-6.5 |
| Watercress | 6.5-6.8 |
| Watermelon | 5.8 |
| Zucchini | 6.0 |
Hydroponic pH Level Chart
Causes Of pH Fluctuations in Hydroponic Systems
Because pH is about concentrations, reducing the volume of water below a gallon will increase the concentration of the elements in your nutrient solution.
Make sure to have a reasonable amount of solution to draw from.
Organic causes include algae and bacteria, which can affect pH.
Algae cause higher pH during the day, as it is using CO2, while bacteria may produce acid from the roots.
You will avoid a lot of these issues by keeping the roots healthy, and keeping your solution slightly acidic when possible.
Great Advice: Using inorganic growing media like gravel and rock that may change the pH of the nutrient solution will generally raise pH. You can mitigate these issues by soaking any inorganic growing media that may raise pH in a weak acid for about 1-2 days before use.
Managing the pH in Hydroponics
You’ll need a pH measuring tool to keep on top of your hydroponic growers pH levels.
The standard litmus paper test will do. It’s inexpensive and easy to buy from swimming pool supply dealers.
Can you achieve adequate readings with it? Not always. There are multiple colours with which you have to match, with the provided hydroponic pH level chart.
Another way to obtain a pH reading is with a pH testing solution. You take a pipette of nutrient solution add this testing solution and you’ll get a reading you can also match to the hydroponic pH level chart.
Although the pH solution is more accurate than ordering the litmus test. The pH testing solution is easily available and a bit more costly.
What to Do: The easiest and most accurate method is the digital pH meter. Toward accuracy, just simply read the steps on your pH meter carefully and use the calibration solution that came with your pH meter.
Summary
To maintain optimal pH levels for Hydroponic, you have to periodically check and modify the nutrient solution pH levels while looking at the hydroponic pH level chart.
Be sure to select the best testing method to improve accuracy and guarantees a good harvest.