Picking the right pH tester is an important step in your hydroponic journey. Often overlooked by beginner hydroponic growers, pH can make or break the growth of your plants. The proper pH allows your plants to uptake the right amount of nutrients and mimics their natural environment so they can thrive. It’s truly the only way to have healthy plants!

Read on to learn why pH is important- and how to test it!

Why pH Is Important in Hydroponic Systems

Maintaining the correct pH in your hydroponic system is vital. pH determines the nutrient availability for your plants. Even if you have the correct nutrient levels in your hydroponic solution, they won’t do any good without the proper pH.

If your pH level is too acidic or too alkaline, your plants will have trouble with nutrient uptake and nutrient deficiencies will follow suit.

The Basics Of pH and EC

It’s important to have the basics down before discussing any further!


What Is pH?

Simply put, pH measures how alkaline or acidic your nutrient solution is. This affects your plants‘ ability to uptake nutrients.

pH particularly affects the nutrient availability of much-needed micronutrients such as boron, iron, and manganese.

A pH of greater than 7 is considered basic (alkaline), a pH less than 7 is acidic, and a pH of 7.0 exactly is neutral.

What Is EC?

EC stands for electrical conductivity. It’s the measure of the soluble and dissolved salts found in your solution. EC is measured using units of electric charge. Some things that contribute to EC include non-essential ions (such as sodium and chloride) along with dissolved nutrients.

EC should be measured when the nutrient solution is originally added, and then periodically thereafter.

Ions are taken up by plants selectively depending on conditions. For example, on dry hot days plants will choose to suck up a lot of water and less nutrients. Meanwhile, mature plants in cooler weather will search for more nutrients and less water.

What Are The Right pH Levels?

Let’s talk about the right pH levels of different crops, along with roughly what the pH of your nutrient solution should be.

Average pH Ranges For Crops

Generally speaking, most crops need a pH ranging between 5.5 and 6.0. If your crop naturally grows in acidic conditions, such as blueberries, it’ll need an acidic pH such as 4.0-5.0. Likewise, crops that need a more alkaline soil enjoy pH levels between 6.0 and 7.0.

Some crops can tolerate a wide range of pH levels. For example, pumpkins will be happy anywhere between 5.5 and 7.5.

Average pH Ranges Of Nutrient Solutions

Hydroponic mineral nutrient solutions usually have a pH level between 5.5 and 6.0 since so many crops thrive in that range. But if your plants need a different pH level than your hydroponic nutrient solution, you can use a pH UP or pH DOWN solution to adjust the levels.

What Changes Your pH Levels

Many factors can change the pH level in your hydroponic system. For example, when your reservoir level drops, your solution becomes more concentrated which can lead to an extreme pH. That’s one of the main reasons you need to keep reservoir levels consistent.

Growing media can also change the pH of your hydroponic system. When you’re testing the pH in a media-based system, be sure to test both the reservoir solution and the leachate that drains from your beds to get an accurate reading.

Organic matter like bacteria and algae can make a huge difference in pH levels. If your pH levels rise and drop throughout the day, algae may be the reason. This is because algae consumes and releases acidic gases throughout the day.

Likewise, if you have diseased roots, the bacteria that are helping decompose the roots will lower the pH by releasing acids into your system.

Choosing the right pH/EC meter

There are a couple different ways to test pH.

pH testing strips

pH testing strips are by far your cheapest option. All you need to do is take a sample of your nutrient solution and dip your litmus paper into it. The paper will change color, and the different colors correspond with different pH’s.

While you can get pH strips that measure anywhere from 0-14, its wise to get ones that measure a smaller pH range to a more accurate degree (for example, one that only measure from 5-9).

Each pH testing strip can only be used once. This method won’t work if your nutrient solution is tinted or colored at all, so it depends on what kind of fertilizer you use.


Hand-held meters are also known as “pen” meters. Many can measure both pH and EC. 

Hand-help meters are faster and easier to use than testing strips. It’s important to keep your probe sanitized and kept wet while you’re not using it. 

Hand-held meters can range anywhere from being incredibly cheap (but not waterproof or very accurate), to measuring to the hundredth degree with an LCD screen. 

They’re convenient in a greenhouse environment because they’re easy for workers to carry around. Some hand-held meters have special needle-like probes that you can put into substrates, while most just measure the liquid solution.


Bench-top meters are put onto tables or benches and have pH and EC sensors connected to a console for you to read. Some consoles can even keep track of measurements over time and give readings for individual nutrients.

Bench-top meters are most common in research labs.


How Do I Choose A pH Tester?

The most important thing to look for in a pH tester is accuracy. For example, if you’re purchasing pH strips, buy ones that test a smaller range of pH with more accuracy. Some hand-held pH meters can read up to a hundredth degree but most gardeners simply need every tenth or .5 degrees.

What Is The Ideal pH For A Hydroponic System?

The ideal pH for a hydroponic system depends on the plants that are growing. Most crops enjoy a pH between 5.5 and 6. Plants that naturally grow in more acidic environments, such as blueberries, will need a pH ranging from 4.0 to 5.0.

Are Cheap pH Meters Accurate?

Cheap pH meters can be very accurate! While some cheap pH meters can only read in whole degrees, you can certainly find some that read every tenth or .5 degrees, which is enough for the average hydroponic gardener.

How Often Do You Check pH In Hydroponics?

Check pH in hydroponics immediately after adding your nutrient solution. Continue to check your pH every few days. 

Why Does My pH Keep Rising In My Hydroponics?

Your pH keeps rising in hydroponics because nutrients tend to be acidic. Therefore, as your plants uptake these nutrients, your solution will become more alkaline and have a higher pH.

What Happens If EC Is Too High In Hydroponics?

If your EC is too high in hydroponics, it can lead to your plants uptaking an excess of nutrients. Too high of an EC can also prevent your plants from uptaking enough water. Ultimately, your plants can be greatly harmed if your EC is too high.

Are All pH Strips The Same?

Not all pH strips are the same. For example, if you get a pH strip that runs all the way from 0 to 14, it will probably only read in whole numbers. But if you get a pH strip with a smaller range that’s more relevant to hydroponics- such as from 5.0  to 9.0- the strip will be able to give a more accurate reading.


Your plants can’t thrive without the correct pH. That’s why it’s so important to have a pH testing system that works for you and your needs. If you’re using strips, you’re better off using ones with a smaller range of pH that read with more accuracy. You don’t have to be rich in order to get an accurate reading!

Check out the rest of our blog to learn about other hydroponic basics!