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10 Picks for the Best Water pH Tester for Indoor Gardening

When it comes to gardening, knowing water pH levels isn’t just for hydroponics. It’s also important for everyday gardeners. pH affects the water used to hydrate plants as well as liquid fertilizers used to pass on nutrients.

Therefore, it’s good to know how to test water pH in your garden.

I’m going to go over the 10 best water pH testers. Keep reading to learn more!

Plants on a kitchen windowsill. Using a best water pH tester keeps your indoor gardening plants healthy.

Our Top Picks

Best Overall:
Apera Instruments AI209

Budget Option Test Strips:
LabAider Test Paper

Professional Grade:
Bluelab Metcom Combo Meter

How Water pH Affects Gardening

You may be aware of the impact soil pH has on plant success. But, what about water pH levels? How does that affect your garden?

Most plants prefer a pH range between 5.0 and 7.0. That goes for soil, water, fertilizer, and other growing mediums.

Closeup of watering can being used to water an aloe vera plant.

The water or liquid fertilizer used to hydrate and nourish the plants could be out of that range. In that case, the plant may be reluctant to absorb any kind of nutrients from the water/fertilizer.

If the water is extremely acidic or alkaline, it could overwhelm and kill a plant altogether.

Plants need proper water levels and nutrients to grow healthy, so water pH is directly related to plant health. Whether you use tap water or nearby natural water sources, it’s important to know what you’re applying to your garden.

Types of Water pH Testers

Digital Tests

A digital water pH tester.

There are two main types of water pH testers. The first you’ll see are digital pH meters. These are the most common, and they’re the best water pH testers for serious gardeners.

Digital pH testers work by inserting a probe or membrane into a solution to measure pH levels. The digital screen will reflect the results.

There is some maintenance involved here. They often require batteries and must be kept clean to avoid corrosion. But, if you plan on testing water pH often, the digital tests are worth the investment.

Digital testers range from professional laboratory-grade to simple and affordable. So, there are options for everyone.

Chemical Tests and Test Strips

Chemical strips used for water testing.

Chemical tests/test strips are the other kind of water pH testers you’ll see.

This may look like a bottle of dye solution that you drop into your water. Or, you may find simple test strips that are dipped into the solution.

Both will turn colors to reflect a certain pH range as indicated on the provided color chart. This is a cost-friendly way to check the pH of your water.

Chemical tests are single-use, so you’ll have to purchase more once you run out. But, it’s a good idea for those who are just dipping their toes into gardening.

The 10 Best Water pH Testers

Now we’ll go over our 10 picks for the best water pH testers we found. We share the pros and cons of each one to help you decide which water pH tester is the best one for you.

Best Overall

Apera Instruments AI209

APERA INSTRUMENTS AI209 Value Series PH20 Waterproof pH Tester Kit, ±0.1 pH Accuracy

My top pick overall for best water pH tester is the Apera Instruments AI209. This digital pocket pH tester has a glass membrane that makes quick pH measurements when dipped into a liquid solution.

The digital screen has large, easy-to-read numbers, and it has an error rate of less than 0.1 pH. It’s also simple to calibrate with the included calibration solution.

When not in use, there’s a shield to keep the glass membrane from being damaged. There’s even a durable carrying case to store in it during the off-season.


  • Easy to read
  • Accurate
  • Comes with a protective shield and case
  • Simple calibration process


  • Requires batteries

Runner Up

Bluelab pH Pen

Bluelab PENPH pH Pen, Digital Meter for Water with Easy Two Point Calibration and Double Junction Probe Test Kit for Hydroponic System and Indoor Plant Grow, White

Bluelab is known for its quality pH testers, and the Bluelab pH Pen is no exception. This digital pH meter is small enough to stick in your tool belt, and it’s fully waterproof. It’s the best water pH tester for those on the go.

Along with pH levels, the probe reads water temperature. And, it’ll alert you when it’s time to be recalibrated or the battery life is low.

Once the pen has been soaked in calibration solution for 24 hours after arrival, it’ll be ready to use. This is one of the more expensive pocket testers, but the accurate readings and quality construction make it worth it.


  • Fully waterproof
  • Accurate
  • Multi-purpose
  • Easy to calibrate


  • Requires batteries
  • Pricey

Dr. Meter pH Meter

pH Meter, Dr.meter Upgraded 0.01 Resolution High Accuracy PH Tester with Backlit Two-Color LCD Display and ATC, 0-14pH Measurement Range with Data Hold Function Digital pH Tester Pen-PH838

The Dr. Meter pH Meter is one of the best water pH testers for a variety of water temperatures. It’s good for testing pH in water temperatures up to 70 degrees Fahrenheit.

Most digital meters are unable to provide an accurate reading at that high temperature. Dr. Meter will automatically compensate for those temperatures, so you don’t have to worry about always testing in cold water.

This is good if you are testing a natural water source that warms up during the summer months.

The tester is also waterproof, easy to calibrate, and will automatically turn off after 15 minutes to conserve battery.


  • Compensates for temperature
  • Waterproof
  • Battery-saving features
  • Accurate


  • Requires batteries

Longest Probe

Hanna Instruments HI98103 pH Tester

Hanna Instruments HI98103 Checker pH Tester with Ph Electrode and Batteries, 0.00 to 14.00 pH, +/-0.2 pH Accuracy, 0.1 pH Resolution

Your test solution isn’t always easy to reach. The Hanna Instruments HI98103 is the best water pH tester for when you need a longer probe. The probe is longer than most basic pocket testers, but it’s still a relatively cost-friendly option.

It has a large screen with clear results, and battery life is usually over 3,000 hours. So, you could go a whole season before you have to worry about a low battery alert.

The electrode can also be replaced, so you can count on using this tester for a long time.


  • Long probe
  • Good battery life
  • Replaceable parts
  • Easy to read


  • Requires batteries
  • Single-purpose tester

Budget Option

Ruolan pH Meter

PH Meter for Water Hydroponics Digital PH Tester Pen 0.01 High Accuracy Pocket Size with 0-14 PH Measurement Range for Household Drinking, Pool and Aquarium (Yellow)

The Ruolan pH Meter is the best water pH tester if you’re looking for a cost-friendly digital meter. For a little more than $10, this tester will do its job well.

It may not last as many seasons as high-end testers. But, if you’re not looking for long-time use, this is a great route.

The Ruolan tester will read pH when the probe is dipped into a solution. The screen clearly reads your results in large numbers, so there’s no need to decipher which number reflects pH.

It also automatically compensates for temperature, which is a useful feature for a budget tester.


  • Cost-friendly
  • Compensates for temperature
  • Easy to read


  • Not as durable as other testers

Budget Option

Vivosun pH and TDS Meter Combo

VIVOSUN pH and TDS Meter Combo, 0.05ph High Accuracy Pen Type pH Meter ± 2% Readout Accuracy 3-in-1 TDS EC Temperature Meter for Hydroponics, Household Drinking, and Aquarium, UL Certified

The Vivosun pH and TDS Meter Combo is the best water pH tester for measuring pH and TDS on a budget. Both test meters have an easy-to-read digital screen with a backlight for reading in the dark.

TDS stands for total dissolved solids. It can tell you the level of dissolved organic and inorganic materials in your test liquid. This is commonly measured in hydroponics as TDS also affects plant growth.

Both of the testers are lightweight, and can easily be stored for yearly use. These are perfect for trying out a digital meter without making a large investment.


  • Cost-friendly
  • Multi-purpose combo
  • Lightweight


  • Requires batteries
  • Not as durable as high-end testers

Best Budget Test Strips

LabAider Test Paper

3 Pack pH.1-14 Test Paper Extensive Test Paper Litmus Test Paper 240 Strips pH Test with Storage Case for Saliva Urine Water Soil Testing Pet Food and Diet pH Monitoring (3 Pack with Storage Case)

While water pH is certainly important, you may have allotted your gardening budget elsewhere. If that’s the case, try out LabAider Test Paper.

It’s the cheapest option on this list of best water pH testers. But, that doesn’t mean it won’t get the job done. The kit includes 240 test strips for only a few dollars.

When dipped into the solution, the strips will quickly change colors. That’s exactly what you count on normal test strips to do, but these are a fraction of the price.


  • Cost-friendly
  • Comes with many strips
  • Easy to use


  • Single-use
  • Only measures pH

Comprehensive Test Strips

SJ Wave 16-in-1 Water Test Kit

16 in 1 Drinking Water Test Kit |High Sensitivity Test Strips detect pH, Hardness, Chlorine, Lead, Iron, Copper, Nitrate, Nitrite | Home Water Purity Test Strips for Aquarium, Pool, Well & Tap Water

The SJ Wave Water Test Kit is the best water pH tester when you’re a new gardener. The kit comes with over 100 test strips. Simply fill the test tube with water, and insert the color-changing strip into the tube.

The strips test 16 different factors in your water. This includes pH, hardness, iron, copper, lead, nitrate, alkalinity, and more. It’s a great way to learn all about the water source you’ll be using in your garden.

When you’re not using the kit, store your strips in one of the included resealable bags with a dry agent. This will keep your strips safe from humidity and ready for next season.


  • Comprehensive test
  • Cost-friendly
  • Good for new gardeners
  • Stores well


  • Single-use strips

Best Test Drops

A2O Liquid pH Test

A2O Water - Made in USA, Water pH Test Liquid (WHT/100-125 Tests) 0.50 Fl Oz

Eliminate the extra step of test strips, and use test drops. Test drops are dropped into the solution, making it change colors to reflect the pH.

This is the best water pH tester for easy results. All you need is the test liquid bottle to get results. That means no keeping up with strips, kits, meters, and calibration solutions.

The drops do only measure pH from 4.0 to 10.0. So, it’s not the best option if you plan on getting results higher or lower than that. But, normal water pH will usually be in that range anyway.


  • Cost-friendly
  • One-step results
  • Easy to decipher


  • Doesn’t measure full pH range
  • Single-use drops

Best for Professional Use

Bluelab Metcom Combo Meter

Bluelab METCOM Combo Meter for pH, Temperature, Conductivity (Nutrient) in Water with Easy Calibration, Digital TDS Tester for Hydroponic System and Indoor Plant Grow, Pack of 1, White

The Bluelab Metcom Combo Meter is the priciest option on this list, but for good reason. This is the best water pH tester for professional and/or experienced gardeners.

The probes measure pH levels, TDS, and water temperature. If it has a low battery or needs calibration, the portable meter will alert you on the easy-to-read screen

You can also connect a soil pH probe to this meter to save you from purchasing two different systems.

Bluelab is a trusted brand, and this specific tester is built to last. It also comes with a five-year limited warranty, so you can feel safe with your purchase.


  • High-quality
  • Adapts to soil probes
  • Comes with a warranty


  • Requires batteries
  • Pricey

Caring for Your Water pH Tester

Once you’ve chosen the best water pH tester for you, it’s important to know how to care for it. This will ensure your tester lasts for many seasons.

Here are some common tips for taking care of your water pH tester:

  • For digital testers, keep the membrane hydrated by storing the tester with the cap on. Your specific meter’s instructions should clarify if you need to fill it with a storage solution.
  • If you test a liquid that leaves dirt or residue on the meter, use a membrane-cleaning solution to remove it.
  • Don’t store your tester in water.
  • Try not to test a liquid that is out of the recommended temperature range.
Closeup of a digital water pH tester.

FAQs on Best Water pH Testers

1. Which is the best water pH tester for me?

The best water pH tester for you depends on how much time you spend gardening. If this is your first year, start out with test strips or drops. They are cheaper than digital testers and are easy to use.

If you’re an experienced gardener, you may want to invest in a digital tester. These can last for many seasons, given they are cared for and of high quality.

2. Do I have to calibrate my water pH tester?

Yes, it’s important to calibrate digital water pH testers. Most digital testers come with a calibration solution that acts as a pH reference for the meter.

The solution will be associated with a certain pH level. Make sure your meter is reading at that level when inserted into the solution.

This should be repeated regularly for the most accurate results.

Keep Your Plants Healthy With the Best Water pH Testers

Closeup of seedlings started indoors.

By using one of these best water pH testers, you can ensure that your plants are able to receive hydration and nourishment. My top pick overall for best water pH tester is Apera Instruments AI209 because of its price point and ease of use. But, any of these testers are great to use depending on your preferences.

Learn all there is to know about getting your garden started by visiting our Seed Starting page where we go over the best products (like water pH testers!) to use, along with growing tips and tricks.

Shopping for your garden can get overwhelming, fast. So if you’re looking for advice on garden tools and garden supplies, then you’re in the right place!