10-in-1 Soil Tester – NPK, pH, EC, Moisture, Temperature & Light

What is a 10-in-1 soil tester?

A 10-in-1 soil tester is a digital instrument that measures ten values of your soil and growing environment with a single probe: nitrogen (N), phosphorus (P), potassium (K), pH, EC, soil moisture, soil temperature, air temperature, humidity and light level. You push the probe into the soil and read the values straight off the LCD screen. No reagents, no soil samples, no colour matching, and no waiting for results.

That means one meter replaces a shelf full of separate instruments: a pH meter, an EC meter, a moisture meter, a soil thermometer, a light meter and an NPK tester.

Which ten values does this soil tester measure?

Value	Range	What you use it for
Nitrogen (N)	0 – 9.9 mg/kg	Leaf and shoot growth, green colour
Phosphorus (P)	0 – 9.9 mg/kg	Root development, flowering and fruit set
Potassium (K)	0 – 9.9 mg/kg	Water balance, cell strength, resilience
pH (acidity)	3 – 9 pH (± 0.1)	Determines whether nutrients are available
EC (conductivity)	0 – 9.99 mS/cm	Total nutrient concentration / salt build-up
Soil moisture	0 – 99 %	When to water and when to leave it
Soil temperature	0 – 60 °C	Sowing time, root activity, greenhouse growing
Air temperature	0 – 60 °C	Climate in a greenhouse or indoor space
Humidity	0 – 99 %	Fungal pressure and transpiration
Light level	Indication on display	Is the plant getting enough light?

Why measure NPK, pH and EC together

These three values are connected. Soil can hold plenty of nutrients while your plant still shows deficiencies, simply because the pH is off and those nutrients are locked up. Feeding will not help there — liming or acidifying will. The other way around, a high EC can mean you have already given too much and the salt level is holding the roots back. Only when you see NPK, pH and EC side by side do you know which of the three is actually the problem.

Nitrogen, phosphorus and potassium (NPK)

Nitrogen drives growth and the green colour of the leaves; a shortage shows as yellowing on the oldest leaves. Phosphorus supports the root system and flowering and fruit set; a shortage causes slow growth and sometimes a purple flush across the foliage. Potassium regulates the water balance and strengthens cell walls, making the plant more resilient to heat, drought and disease; a shortage shows as discoloured, scorched leaf margins.

pH – the acidity of your soil

pH determines which nutrients a plant can actually take up. Most garden and vegetable crops do well between pH 6.0 and 7.0. Rhododendron, azalea, hydrangea and blueberry want it more acidic (pH 4.5 – 5.5), while a lawn performs best around pH 6.0 – 6.5. Always measure before you lime: spreading lime without measuring is the most common mistake in the garden.

EC – the nutrient concentration

EC (electrical conductivity) measures how many dissolved salts and nutrients are present in the soil. It is the fastest check on over- or under-feeding. If EC climbs in a pot or grow bed, salts are accumulating and the plant starts losing water instead of taking it up — time to flush.

Soil moisture, temperature, light and humidity

Soil moisture tells you whether watering makes sense, even under a dry top layer. Soil temperature determines when you can sow and when roots become active again. Light and humidity describe the conditions the plant has to cope with — for houseplants, greenhouses and grow lights that is the missing half of the picture.

How to use the soil tester

1. Clear mulch, grass or loose top layer from the measuring spot.
2. Lightly moisten very dry soil and wait about 30 minutes; bone-dry soil gives no reliable reading.
3. Insert the probe straight and fully into the soil, at least 10 cm deep, down to the root zone.
4. Wait until the reading on the display is stable, then note it.
5. Measure at three to five spots and take the average — soil varies a lot per square metre.
6. Wipe the probe clean and dry after use. Do not leave the meter in the ground.

10-in-1 soil tester, 4-in-1 meter or chemical test kit?

	10-in-1 soil tester	Basic 3/4-in-1 meter	Chemical test kit
Measures NPK	Yes, N, P and K separately	No	Yes, as a colour indication
Measures pH	Yes, digital reading	Analogue needle	Colour matching
Measures EC	Yes	No	No
Measures light and humidity	Yes	Light sometimes	No
Result	Instant, in numbers	Instant, indicative	After 10 – 30 min, indicative
Reusable	Unlimited	Unlimited	Limited number of tests
Running cost	Batteries only	None	Buy new tests

In short: a test kit gives you a snapshot in colour, a basic 3-in-1 meter gives you a direction, and this 10-in-1 soil tester gives you numbers you can build a feeding plan on — and check the results of.

Who is this soil tester for?

• Vegetable and allotment gardens – know what your soil needs before the season starts.
• Lawns – check pH before liming and track nitrogen through the season.
• Ornamentals and borders – put acid-loving plants in the right spot.
• Houseplants and potting soil – keep an eye on salt and nutrient build-up in pots.
• Greenhouses and grow lights – follow soil and climate with one instrument.
• Nurseries, orchards and agriculture – fast field readings across multiple plots.

Frequently asked questions

How do I measure the pH of my soil?

Insert the probe at least 10 cm into moist soil, wait until the reading stabilises and read the pH off the display. Measure in several spots and take the average. This meter reads from pH 3 to 9 with an accuracy of 0.1 pH, which is more than enough for any garden, lawn or potting soil situation.

Can I test my soil myself without a laboratory?

Yes. A digital soil tester measures NPK, pH, EC and moisture on the spot, without sending a sample away. A lab analysis is more precise and also covers trace elements, but costs time and money per sample. A digital meter can be used as often and in as many places as you like — which makes it the better tool for finding differences within your own garden and for tracking the effect of feeding.

What is a good pH value for my garden?

For most vegetables and border plants pH 6.0 – 7.0 is ideal. A lawn does best around pH 6.0 – 6.5. Acid-loving plants such as hydrangea, rhododendron, azalea and blueberry want pH 4.5 – 5.5. If your pH is too low, raise it with lime; if it is too high, lower it with acidic compost, peat or sulphur.

How do you measure NPK in soil?

This soil tester measures nitrogen, phosphorus and potassium separately through the probe and shows a value in mg/kg for each. You can see immediately which of the three is lagging and choose a targeted fertiliser instead of defaulting to a universal NPK granule.

What does the EC value of soil mean?

EC stands for electrical conductivity and indicates how many dissolved nutrient salts are present in the soil. A low EC points to poor, depleted soil. A high EC means a lot of salt is present, often from over-feeding, and the plant will struggle to take up water. EC matters most in potting soil, greenhouse growing and hydroponics.

How deep should the probe go?

At least 10 cm, and preferably down into the root zone of the plant you are assessing. Measuring too shallow mainly reads the dry top layer and gives moisture and nutrient values that are too low.

How often should I test my soil?

At minimum at the start of the season, before you feed or lime, and again halfway through the growing season to check the effect. In pots, greenhouses and under grow lights it pays to measure monthly, because EC climbs fastest there.

Does this soil tester work for houseplants and potting soil?

Yes. The probe is suitable for potting soil, grow beds and open ground. Just make sure the pot is deep enough to insert the probe at least 10 cm, and avoid pushing it straight through the root ball.

Do I still need a separate moisture meter or light meter?

No. Soil moisture, light level, air temperature and humidity are all built into this instrument. If you want continuous, remote monitoring rather than manual readings, a wireless sensor with an app is an addition — not a replacement.

Are batteries included?

The meter runs on AAA batteries. Check on delivery whether they are included; shipping rules for batteries mean they are not always supplied as standard.

Specifications

Model	OW-102
Functions	10 in 1
pH range	3 – 9 pH, accuracy ± 0.1 pH
EC range	0 – 9.99 mS/cm
Nitrogen (N)	0 – 9.9 mg/kg
Phosphorus (P)	0 – 9.9 mg/kg
Potassium (K)	0 – 9.9 mg/kg
Soil moisture	0 – 99 %
Soil temperature	0 – 60 °C
Air temperature	0 – 60 °C
Humidity	0 – 99 %
Light level	Yes, indication on display
Display	LCD
Dimensions	309 × 63 × 30.5 mm
Material	PC + ABS
Power	AAA batteries
Weight	Approx. 500 g including packaging
Certification	CE, RoHS, UKCA, IEC 62321
Warranty	1 year