If you’re hydroponic-gardening, then you already know that the pH balance of your system is important. But, like a toddler learning to balance on a two-wheeler for the first time, it can be tricky to keep pH stable and in the optimal range.
In this article, I’m going to show you the basics of how you can easily maintain pH balance in your hydroponic garden. We’ll cover everything from what pH is and why it matters, to how to measure and adjust it quickly and easily.
Once you’ve mastered the balancing act of pH stability in hydroponics, your plants will be healthier than ever — happy growing!
Contents
What is pH and why is it important in hydroponic systems?
If you’re into hydroponics, you’ve undoubtedly heard of pH levels before — but do you know what it is and why it’s so important? Well, pH measures the acidity or alkalinity of any given solution.
In hydroponics, it’s used to measure the acidity or alkalinity of the nutrient solution your plants are growing in. The pH in a hydroponic growing medium is directly related to the ability of plants to absorb essential nutrients.
It’s a balancing act when maintaining pH levels — too much or too little can put stress on your plants and diminish their growth potential.
You want your nutrient solution to have an optimal pH range that allows for optimum nutrient uptake. That way, your plants will have access to all the essential vitamins and minerals they need for healthy growth and development.
Since plants can take in certain nutrients better at varying pH levels, this drifting process works nicely. Your goal is to keep a pH stable that falls between 5.5 and 6.5, depending on the growing plants in your hydroponics system.
For example, some crops might require slightly lower pH while some may need slightly higher levels. So make sure you read up on the typical pH ranges requirements of whichever crops you are growing to ensure healthy growth.
What factors affect pH levels in hydroponic systems?
To maintain pH stability in your hydroponic systems, it’s important to look at the factors that can affect it. Specifically, you should consider factors like crop type, nutrient concentration, and water quality.
Different types of crops require different levels of acidity for optimal plant growth. It may be helpful to look up the ideal pH for your desired crop, as this will make it easier to adjust the pH in your system accordingly.
Next is nutrient concentration. Typical pH ranges for nutrient systems start with a pH between 5.5 and 6.0, the optimal level for most crops. High levels of mineral nutrients in hydroponic solutions can also cause pH changes.
This is especially important to keep an eye on when adding new nutrients or when dealing with an established system with many vegetation cycles in its history — the latter often leads to higher levels of accumulated mineral salts. In a hydroponics system, the plants fail to benefit from organic matter which can regulate pH.
The final factor affecting pH is water quality, which can vary significantly depending on where you live and what kind of source you’re using for your water supply. Many sources have high levels of carbon dioxide or dissolved minerals that contribute to acidic soil conditions —which in turn requires more frequent adjustments of the pH level in your hydroponic system.
How to test the pH level of a hydroponic system correctly
It’s essential to control pH level of your hydroponic system to ensure plants are getting the proper nutrition. The pH scale measures the strength of an acid or base with a range from 0-14— the lower the number, the more acidic, and the higher the number, the more basic.
To get an accurate pH reading in media-based systems, test the pH in the reservoir as well as that of the solution that drains from the beds or other containers that hold the plants. The first needs to be taken from your nutrient reservoir, and the leachate, which is the chemical runoff.
Both inorganic and organic matter can alter pH levels in hydroponics systems.
For most plants, you need to maintain a slightly acidic pH level between 5.8 and 6.3. To make sure your nutrient solution is within this range, you have to test it frequently with a simple pH testing kit.
Here’s how:
- Fill a glass or plastic container with hydroponic solution.
- Dip your testing probe into the liquid and wait for 10 seconds until you get a reading on the panel or meter that comes with your testing kit
- If your reading is outside of the desired range (5.8-6.3) then you need to adjust accordingly by adding pH up or down solutions to reach the appropriate level
- Repeat tests every couple of days to make sure levels remain stable
- Test any new water batches you add separately!
Testing your hydroponic system’s pH level regularly is important if you want to create an effective environment for plants to grow healthy and strong — and now that you know how it’s easy!
Hydroponic pH pens are the most reliable option, but unfortunately, the most expensive. Of course, because it’s a digital reading, it might be worth the expense. After all, with a digital reading, there’s no mistaking a small difference in colors.
Test strips and liquid test kits are the least expensive and are available at pool supply stores and garden centers.
How to adjust your hydroponic system’s pH level
If your hydroponic system’s pH level is too low or high, it can cause severe damage to your plants; they’ll become stunted and discolored, and might eventually die. To prevent that, you need to know how to adjust your system’s pH level to keep it stable.
First off, check your hydroponic reservoir every other day with a reliable pH meter or test kit.
If the pH is off, you can use a few simple tricks to bring it back into balance:
Increase the pH.
To increase the pH in your system, add 1 tsp of baking soda for every five gallons of nutrient solution. If you need more than that, add 5 ml of a commercial-grade alkalinity supplement for every 10 gallons of solution.
Various chemical compounds can be used as pH adjusters, such as nitrate, ammonium nitrate, and calcium salts. If the pH of the hydroponic growing medium is too low, you can add lime water or kalkwasser to increase the pH. Kalkwasser contains calcium carbonate, which converts to calcium bicarbonate when exposed to high pH levels.
Decrease the pH.
A pH level above 6 or 6.5, however, can cause iron deficiency. To adjust pH levels in your hydroponics, use 1/2 tsp of citric acid per five gallons of solution.
You can also use 2 ml of phosphoric acid in place of citric acid if you want to lower and stabilize the pH quickly.
One of the more straightforward is NFT (Nutrient Film Techniques) as your solution is in direct contact with the plant’s root systems.
Now that you know pH adjusters for your hydroponic system, all that’s left for you to do is monitor levels regularly, so you don’t run into any unexpected problems down the line.
Key tips on keeping pH stable:
Maintaining pH stable in hydroponics is an absolute must if you want to make sure your plants stay healthy, strong and full of life. Here are some key tips that you should keep in mind when it comes to managing the pH level of your hydroponic systems:
Use pH meters.
The most important tool that you need to use is a pH meter. This allows you to accurately measure the pH level in your hydroponic systems so that you can be sure that it is at the proper level. Make sure that you are regularly testing the pH levels so that can make adjustments as needed.
To get an accurate pH reading in a media-based system, test the pH of the reservoir solution as well as the solution (leachate) that drains from the beds or bags that hold the plants.
Using automatic pH adjusters will allow you to quickly fix any pH fluctuations before they have had a chance to affect your plants.
Use acidic or alkaline solutions as needed.
If the hydroponic pH levels get too far off from where they need to be, then it’s time to intervene and make the necessary adjustments. You can either add an acidic solution or alkaline substances, depending on which direction pH balancing needs to go. Just make sure to add these solutions very slowly so that you don’t shock your plants!
Keep in mind: When dealing with pH level treatments, you must be cautious since the liquids will burn as you move closer to either end.
Regularly monitor nutrient solution level.
The nutrient levels in the water also alter pH levels, so you must ensure that they stay within the proper range as well.
Because of the pH sensitivity, you do need to follow recommended doses and take separate readings, in case you have to adjust again.
The aim when making your adjustments is to make sure there is no nutrient lockout. By regularly monitoring both the nutrient levels and the pH levels, you can ensure that your plants stay healthy.
By taking these simple steps, you can rest assured that your hydroponics system has a stable pH level — which will help ensure optimal growth for all of your plants!
Troubleshooting problems with low or high pH levels
If you’re having trouble with your pH levels, it’s time to start troubleshooting. Low pH or high pH can hurt the roots of your plants, which is why it’s important to keep a close eye on your nutrient solution and adjust accordingly.
Everything can go wrong due to the wrong pH conditions for a long time will take a long time to recover and in some cases may go into what’s called “nutrient lockout”, and may not recover at all.
Keep track of pH level.
It can help to keep track of all the adjustments you make over time, so you have a clear understanding of what works best for your setup.
Make sure you’re measuring the right pH level by testing with a reliable device, like a probe-style meter. Then use indicator paper strips or drops to double-check the readings.
Balance your nutrients.
Nutrient deficiency in hydroponics systems can cause erratic pH levels. For example, if there’s too little nitrogen in your solution, that could mean more nitrogen gas bubbles moving into the roots which could be why pH levels rise.
To adjust nutrient levels, it can help to test for conductivity and adjust according to the size of your reservoir — the larger the reservoir, the less concentrated nutrients need to be.
Monitor temperature & light intensity.
Temperature also plays a role because as temperatures get higher, there will be more evaporation from your nutrient solution, leaving salts behind which can raise its pH level.
And when light intensity increases, it usually causes greater plant growth — that means more roots and nutrients consumed, which can lower pH if not accompanied by extra nutrients added back into the system.
An automatic pH controller is implanted in your hydroponics system to set the pH right.
It is a recommendation to use distilled or reverse osmosis water instead of tap water. A reverse osmosis water kit is a simple and effective way to treat your water and pay for itself over time.
If small adjustments just don’t seem to do it, then it might be time to start over with fresh water and new nutrients — but with all this knowledge on hand, you will no longer be wondering how to keep pH stable in hydroponics.
Conclusion
In conclusion, balancing pH levels in hydroponics can be quite a challenge, but is a necessary step in the process. Hydroponics offers the potential for larger yields and easier maintenance than soil cultivation, but with the added challenge of controlling and monitoring the pH of the nutrient solution.
Weakly acidic ion exchange resins are a great way to provide stability to a recirculating hydroponic system, they are also low-cost and can be regenerated easily. To be successful in hydroponics, you’ll need to pay close attention to pH levels throughout your growth.
With the appropriate tools, such as a pH-adjustment buffer, you’ll be able to manage your nutrient solution for optimal pH balance and unlock the potential benefits of hydroponics.
FAQ
Why does my pH keep going up in my hydroponics?
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How do you balance pH in water hydroponics?
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Learn More: pH in Hydroponics