How to Maintain pH Balance in Hydroponics: In-depth Instruction

There are a few terms of a hydroponic system that might seem confusing to you if you are a new grower. The pH is one of the major fathoms that you have to understand and control regularly. Here we will talk about how to maintain pH balance in hydroponics to help you grow your plants better.

The lights, spacing, and nutrient requirements are the factors that we focus much on while starting a hydroponic system . But the pH is so important that its imbalance can affect the growth of the plants. It might take some time to understand but it will bring good fortune to the system.

A little imbalance of pH is not a serious threat. But if it is too high or too low, then the plants will not be able to take nutrients from the soil. Later it will cause a lack of thriving to the whole hydroponic system. This is why you have to pay extra attention to the pH balancing.

How to Maintain pH Balance in Hydroponics?

To successfully grow plants in hydroponics system , it is must to maintain pH balance. The first step you have to do is calculating the pH level. If you find any imbalance, take immediate steps. You may have many options, but using the ‘pH up’ or ‘pH down’ products according to the overall condition is the best way.

To learn the whole procedure in-depth, some other relevant factors should be considered. Let’s proceed.

The pH Level in Hydroponics System – How Important It Is

The nutrient mixture of any solution is very important as they help the plants to grow and thrive. If the level is out of range then the plants will lose the nutrition absorption ability.

Tolerance is not the same for every mineral. And when it is to the respective pH level, the difference is a must. As all the growers know that, macronutrients are the prime demand of the plants. But they will not intake macronutrients if the pH level is too high or too low. So, nutrient deficiency will occur here.

While applying macronutrients, pouring in smaller doses is required. Otherwise, the opposite side will have some effect that is bad for the whole scale. In low pH, plants can absorb more nutrients that are not needed. Because of it, the plants may face toxicities. In high pH, nutrients will be deficient.

You must understand the elements that affect the pH level to maintain the nutrition balance of a hydroponic system.

Growing Medium:

As a result of pH imbalance, the growing medium faces the maximum effects. There might be a release of magnesium and calcium into your solution from the calcareous rock. These will reach to water and you have to adjust as soon as possible.

As coco coir contains sodium chloride, it can affect the pH level. If it happens, then you have to soak it thoroughly to wash all the possible contaminants if there is any.

Perlite is another common growing medium. There will be no pH swing in any side of the solution as its pH is 6 to 8. For Rockwool, it is 7 to 8.5 that require no washing before using.

For some reason, if you need to know about growing medium, then you must use a hydroponics system. I have talked details about growing media for hydroponics in this article.


The temperature needs a lot of adjustment and there are things to learn properly. The ideal condition is 65 to 80 degree Fahrenheit for almost all the solutions. Warmer than this will evaporate water faster which is not expected.

If this happens, the ratio of nutrients to water will be increased, and your reservoirs will start clinging. The smaller reservoirs will be more affected than the large ones. The temperature must vary for a different region. Some hydroponic growers either use a water heater , or a water cooler to keep the solution temperature under control.

What is pH?

In every hydroponic system, there are two components named acid and alkane. The pH is a measure of these two. It has a logarithmic scale that runs from 0 to 14. It is proven that a pH of 4 is ten times more acidic than a pH of 5. So, it will be a hundred times more acidic than a pH of 6.

With pure water the neutral value is 7. It means, if the value comes below 7 then the solution is acidic, and in case of above, it is alkaline. Now you should not compare the optimal pH level between hydroponics and soil plants. There is a difference and it will hamper the growth of the plants.

There are a few hydroponic crops that are very common around the growers. For those, the pH level is should be 5.5 to 6.5. If you are using an automatic controller for the crops, you should keep the range from 5.8 to 6. To maintain this level, it is a must to dose acid regularly.

The pH range affects the solubility, availability, and uptake of several of the essential nutrients for all the hydroponic crops. So, there is no way to ignore the necessity of it.

We mentioned before that the level should not cross 7 in the scale. If it happens then the taken nutrition will work less efficiently. It will cause a deficiency of iron in the solution even if the plant has a sufficient amount of it.

Calcium is the most affected among others because of its high pH value. It forms insoluble salts that precipitate out of the nutrient solution. As a result, whitish deposits will be visible on the reservoir walls, equipment, and channels. All these misbalancing are harmful to the plants. The appearance of foliage, tip-burn, and leaf cupping is the result of these.

If you are an inexperienced grower, these problems might seem bad nutrition formulation to you. So, before you start growing, you should know what pH is and how to maintain pH balance in hydroponics.

What is the pH Ranges for Crops

For hydroponic crops, the optimal pH range is 5.5 to 6. But you may see some exceptions for a few crops. The mentioned range is perfect for many fruits and vegetables, such as, apples, melons, tomatoes, beans, and squash. For blueberries, 4 to 5 is been considered as the ideal.

Using a separate nutrient reservoir with similar pH ranges is a wise way to go. On the other hand, there are some crops with wide optimal pH level.

For kale, pears, and onions, the pH range is between 6 to 7as they require alkaline conditions to their solution. For the pumpkin, it is 5.5 to 7.5 and for mint, you have to set 7 to 8 as an ideal range.

What is the pH Range for Nutrient Systems

The pH level is 5.5 to 6 for the nutrient products of a hydroponic system. There is a specific formulation for the nutrients to calculate. In any solution, the presence of acid is vital and it should be in a proper quantity. This effect on ammonium is bigger than calcium salt.

If the pH rises by any chance, there will be a more alkaline solution in the system. For proper plant uptake, the pH levels should be certain for specific nutrients. There is always a chance of misbalancing in the solution if the pH level is wrong.

The plants may face calcium deficiency, develop of magnesium and copper or iron toxicities if the pH level drops below 5. Moreover, there can be an iron deficiency if the pH level reaches above 6 or 6.5.

How to Maintain pH Balance in Hydroponics

Change of Ph Level in Hydroponic System – Why and How

The pH level of a hydroponic system can be changed due to several reasons. We have listed a few based on our research to help you out and for better understanding.

  • If the amount of nutrient solution drops below one gallon, the plants start to absorb them and become more concentrated. As a result, the pH level will fluctuate widely. So, it is important to monitor the nutrient solution level, test the pH regularly, and take care of the nutrient solution level.
  • Organic and inorganic matters are highly responsible to change the pH levels. Gravel and other inorganic growing media act as a buffer in any solution. It can raise the pH level within a short time.

If the environment is natural, the soil can also act as a buffer. In a media-based system, you must test the pH of the reservoir solution to get the exact pH reading. Moreover, you should also take the reading of the solution that drains out from the beds or the bags. By doing this, the readings will be perfect.

  • Bacteria and algae affect the most to the pH level. If it is algae that are affecting, then the pH will rise in the morning and will drop down in the evening. This happens because algae consume carbon dioxide during the day that assists to rises the level and falls later.

Root diseases can cause bacteria that drop the pH level suddenly. After a while, the roots will decompose and acid will mix in the solution.

How to Maintain the pH Level

Testing is the first and prior thing that you can do to maintain the pH level. There are various testing supplies available at garden centers and pool supply stores. The least expensive ones are liquid test kits and test strips. For an accurate result, you should pick the digital pH meters that offer repeatable results.

You have to continue testing no matter whatever testing instrument you have. If the nutrient level has been adjusted recently, the best is to do the testing daily. It is good for the solution and will make you experienced doing well in the future.

The test results from the supply reservoir can be used if you are going with a re-circulating system. The pH level can be adjusted based on the same result. But it changes frequently for a media-based system as the solution travels from the supply reservoir.

You can also bring the “pH up” and “pH down” products to maintain the levels perfectly. All these are available in dry or liquid form. Just follow the label instructions to complete the using process. Weak acids like vinegar or citric acid can be used for short term results or small systems.

There is an automatic pH controller which will give you consistent results but will cost more than pH up or down products. For the re-circulating system, this controller works the best.

In case the water of the solution is hard, it might cause high pH levels because of the buffering effect. To get rid of this problem, the reverse osmosis system is the preferable way.

You should check our article for how to maintain ph balance in hydroponics?

What are the Benefits of Maintaining pH Levels?

For proper growth and thrive, each plant needs a suitable condition. The monitoring is a time-killing task that you may dislike. Moreover, adjusting the pH level is not the simplest thing to do. But all these will seem worth it when your hydroponic system will be healthy, fresh, and lively than ever.

To keep the plants in good condition you must know their pH ranges. It will help to take necessary actions whenever you see any misbalance in the pH level. To measure the level, you have several options to choose from. As a beginner, pH maintaining can be difficult but the results will make you happy.

What to Do for Different Hydroponic Systems?

For re-circulating and media-based systems, checking the pH is quite easy. For these, you have to measure both at the nutrient supply reservoir and then draining out the solution. But some other hydroponic systems have not the same pH levels and balancing as well.

You will find a slight difference in pH between the feed nutrient and the leachate solution as they grow rapidly. The solution flows past the roots, the pH changes. Also, there might be a pH influence when the ions have been absorbed or released.

You should use the measured pH of the leachate draining from the plant’s root system to adjust the pH at the nutrient supply reservoir. If the pH of leachate is 6.9, for feed solution it will be 6.2.

The root system should experience the pH just like down to the point where the drainage solution starts to come down to 5.8 to 6. If you follow this method, any rapidly growing plants will grow and thrive as expected.


If you are a hydroponic grower, you have to understand what the plants need and how to keep them healthy by adjusting the pH level. As a result, you will have the best plants after the harvest. Maintaining the pH is not the toughest thing to do but the challenge is to monitor it on a regular basis.

Any testing tool or adjustment product you need, you will find them easily at an affordable price. Growing a lot is not the last thing to do; you have to make sure the uptake of nutrients by the hydroponics plants is maintaining the pH balance.

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