Best pH Meters for Hydroponics

Thomas Angas by Thomas Angas | Last Updated: July 31, 2019

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If you’re coming from a traditional gardening background, hydroponics gardening can often have you feeling more mad scientist that green fingered gardener. When I first got into hydroponics I didn’t realise that I’d need to keep track of everything from nutrients and ventilation right through to water pH levels and overall system health.

The result was that my plants failed and I was left frustrated.


Never one to give up, I took a look at where I was going wrong and it turns out I wasn’t keeping a close enough eyeon the pH level of the water. See it turns out that in a hydroponics system, you test the soil constantly, something I never really worries about when I was soil based gardening.

In this guide we take a look at the best ph meters for hydroponics that will help you keep your system running at just the right levels.

Picture of a ph meter testing solution

Why Monitoring Your pH is so Important

Was the last time you read about pH levels back in highschool chemistry class?

Don’t worry, we’ve got a quick refresher for you.

You’re a gardener not a chemist, why should you worry about pH levels?

Well for a start, whether you’re a hydroponics gardener or a traditional soil based grower, the pH of your soil plays a huge part in how your plants grow.

Not only does the pH of your soil determine what plants you can grow, it also determines the nutrients available in the soil.

Basically, if your pH isn’t right your plants won’t be able to properly absorb the nutrients that are in the soil.

You don’t need to be exact but you do need to keep your pH levels between 5.5 and 6.5 as this tends to be the most ideal range.

For those striving for perfection, 6.2 is the target to aim for.

How Does a pH Meter Measure pH?

With pH monitoring being so important to your grow setup you’re going to need something to help you keep an eye on the levels.

That’s where a pH meter comes in.

So how does a pH meter measure pH? We’ll there’s a long answer and a short answer…

The short answer is that a pH meter measures the hydrogen-ion concentration of the water.

The long answer is outside the scope of this article but this is a great guide if you’re interested in understanding exactly how they work.

What’s The Difference Between Manual pH Testing vs. Digital pH Meters?

When it comes to testing pH there are two options:

Both have pros and cons which we’ll explore below.

Manual pH Test Kits

Manual pH testing is done using a kit, similar to the kind you’d use to test pool water or might have used in science class.

They are really simple to use and with only a couple of parts, are very cheap.

If you’re just getting started with your first hydroponics system then a manual testing kit is a great option.

The downsides are that they’re nowhere near as accurate as digital test meters and take longer to provide a reading.

Digital pH meters

If you are looking to improve the results you’re currently getting from your hydroponics grow then you NEED a digital pH meter.

A digital meter is significantly more accurate than testing strips and solutions and a good meter will last you a lifetime.

Testing is much faster which means that you can spend more time working on other parts of your system.

However, all this convenience comes at a price. The very best meters on the market do come with a premium price tag but that said, they will last you years and years.

You’ll also need to keep a digital meter calibrated in order to keep producing accurate readings.

How To Calibrate a Digital pH Meter

When you buy a digital pH meter, the most important thing you can do is keep it calibrated.

To calibrate a meter you need a buffer solution – a laboratory certified reference point for your meter. By using a buffer you can be sure that your meter is reporting accurately.

Thankfully, calibrating your digital pH meter is a breeze.

Here’s how you then calibrate your meter:

1. Place your meter or meter probes into the buffer solution and take a reading.
2. Adjust the meter reading to match the buffer solution using the guide provided.
3. Repeat the process again to check the reading.

Calibration Tips

If in doubt, the video below can help.

Caring for your pH Meter

As we’ve mentioned, if you take care of your pH meter then it will last you a lifetime.

Your instruction manual will tell you exactly what care is required, however, the below will be useful for every meter:

The Best pH Meters for Hydroponics (manual)

If you’re just starting out or are on a tight budget then you’ll generally want to go for a manual pH test kit.

General Hydroponics pH Testing Kit

Our recommendation would be to use the General Hydroponics pH Testing Kit.

As the name suggests, the kit contains all you need to measure your hydroponics setup and includes:

  • 8oz pH UP (potassium hydroxide),
  • 8oz pH DOWN (phosphoric acid),
  • pH Test Indicator,
  • Test vial

What We Like

  • Super simple to use making it great for new gardeners
  • Contains everything you need to get going

What Could Be Better

  • The kit could benefit from an extra pipette so you can have one for acids and on for bases


I like this kit and if you’re just getting started with hydroponics then it’s a great choice.

See the price

The Best Digital pH Meters

For those wanting to be more scientific about their grows then a digital ph meter is a great choice.

Easy to use, these meters will give you an accurate reading every time.

Bluelab pH Pen

The Bluelab pH pen is my personal favorite and the one that I’ve recommended to countless other growers. It’s extremely accurate and can measure both pH and temperature with readings displayed on the back-lit LCD.

What We Like

  • Easy to measure pH and temperature with one reading
  • Waterproof

What Could Be Better

  • The calibration kit is necessary but sold separately
  • Bulb on the sensor is fragile


The Bluelab pH pen really is one of the better digital pH meters available. While it does need to be calibrated, if you look after it then the meter will last you a lifetime.

See the price

Oakton EcoTester

If you’ve decided to upgrade your manual pH testing then the Oakton EcoTester is a fantastic first choice.

The Oakton EcoTester is can test both pH and temperature and has all the functionality of more expensive testers while being just as easy to use.

What We Like

  • Friendly on the wallet
  • Reliable readings
  • Waterproof and dust proof

What Could Be Better

  • Needs calibrating more often than others


The Oakton EcoTester is a solid choice if you’re looking for a digital pH meter but keep in mind that it will need calibrating more often than the Bluelab pH pen.

See the price

The Best Digital pH Combo Meters

For those gardeners looking to go beyond pH and water monitoring, there are a number of great digital pH combo meters available.

While these are more expensive, if you’re going to be monitoring multiple metrics then they do work out cheaper than buying individual meters.

Bluelab Combo Meter

The Bluelab Combo meter seems to be the most popular choice of combo meters.

The unit allows you to test everything from pH and temperature to parts per million (PPM), electrical conductivity (EC) and total dissolved solids (TDS) which are all vital for those with advanced hydroponic setups.

What We Like

  • Huge range of measurement options available
  • Comes with spare probes

What Could Be Better

  • Not waterproof


Once you start looking to dial in your hydroponics setup then you need to measure everything. With the Bluelab Combo Meter this is a breeze.

See the price

Bluelab Guardian

While this is the most premium test meter on our list, it’s ideal for those with large hydroponic setups or even commercial operations.

Unlike other meters that you might use daily to test, the Bluelab Guardian is always on, providing you with real time information on how your system is running which allows you to make changes quickly.

What We Like

  • The display is clear and easy to read.
  • The data is accurate.
  • Flashing alarms let you know if your numbers are out of the normal range
  • The kit contains many different accessories

What Could Be Better

  • As a daily meter, the Bluelab Guardian requires calibrating more often and needs more maintenance.


This is really the very best digital pH meter for hydroponics on the market, however, it might be overkill for those gardeners with smaller setups.

See the price

Hanna pH/EC/TDS Meter

Hanna has a long history of producing highly accurate meters that give precise readings.

The Hanna pH/EC/TDS Meter is a great little tools for measuring water pH, temperature, electrical conductivity (EC) and total dissolved solids (TDS).

It also comes with a built-in calibration reminder to alert you when the unit needs recalibrating.

What We Like

  • Simple to operate and calibrated
  • Calibration reminder
  • Wide range of measurements available

What Could Be Better

  • Doesn’t come with spare probes.


The Hanna pH/EC/TDS is one of the best ph meters for hydroponics and contains all you need for testing.

See the price

The Bottom Line

So there you have it, hopefully this guide has introduced you to the world of pH meters and has helped you pick the best digital pH meter for hydroponics.

Thomas Angas, the founder of Authority Gardening lives with his wife and two darling pups. He spends his free time writing, hiking and learning how to become a better gardener. He launched Authority Gardening in 2017 to help people all over the world their gardens grow.