The best-selling 3-in-1 Water Meter is now available in Mint. A gorgeous, soothing shade somewhere between sage-green and duck egg blue (I've tried to capture it in different lights to give you the truest idea of the beautiful colour). A great tool for peace-of-mind to help you decide when to water, and to check conditions for light and soil pH are in the range your plants prefer. Plus in a colour pretty enough to leave it out ready to use when needed.

How to use 

To check soil moisture

Push the switch far left to the MOIST setting. Gently insert the probes, keeping them vertical, roughly half way between the plant's stem and the edge of the pot (if the soil's too compacted, don't force the probes, break the soil up with chopsticks or a knife first). Too close to the edge of the pot tends to read dry as moisture and naturally draw inwards as it dries out.

Go down about 3/4 of the way into the pot, to check conditions at root level near the bottom. Wait 2 minutes and the needle will indicate the moisture level. I did find the probes need to go down at least 12cms or so for accurate readings - the length of the probes is 17.5cms - so if you have some plants in small pots less than 12cms deep, get the shorter Soil Sensor as well or instead.

READING THE RESULTS: There are 3 zones: 1 to 3 is the red zone (dry), 4 to 7 is the green zone (moist), and 8 to 10 is the blue zone (wet). The dial says dry, moist or wet on it.  Water according to your plants preferences. Getting multiple readings is normal as moisture won't be evenly distributed in the soil, so take a couple of readings in different spots. 

TESTS IN REAL LIFE: This is the most helpful setting and the main reason I use this tool. I tested a range of plants, from recently watered to moist to dry, and it's pretty accurate providing you know how these workk > I know they look so simple, but there are still simple things to do (and not do) to get the best readings >

I pay attention to the zone on the dial (dry, moist, wet) rather than the exact number. Keep in mind these work on indoor and outdoor plants in a range of soils (see more about substrates below), so unless you've got an indoor plant growing in the same high water-holding soil you would use outdoors, you shouldn't get a 'wet' reading on an indoor plant.

I've had it happen lots of times where plants I thought were dry, and would have watered, turned out were still wet down at root level, because these probes go down deeper into the pot than I can possibly test with my finger. I find these super handy if you're not 100% sure and worried about over-watering. 

As a light meter

Move the switch to the middle setting above the word LIGHT. There's a small light sensor panel at the front of the meter. Face that towards the light source in the same spot you plan to put your plant. 

READING THE RESULTS: 0 is Dark. From 200 to 1000 indicates low to medium light. 1,000 to 2,000 is the medium to bright zone (direct sunlight registers over 2,000).

TESTS IN REAL LIFE: The gauge has a range 0 to 2,000 lux but I found that what I'd call medium light areas still register in the low to dark zone because this meter is made for both indoor and outdoor use, so allow a bit of leeway with this setting and use it more as a guide for indoors. Indoor readings will always be on the low to medium range even in bright indirect light, because 'bright' light indoors is still so much darker than direct sun outdoors. Direct sunlight will be read at the other end of the dial.  

To check soil pH

Move to switch to the setting on the right where it says PH. Put the sensors quite deep in the soil (at least 3/4 of the way down the pot, for pots deeper than 12cms). Wait 2 minutes for the result to show on the pH gauge.

READING THE RESULTS: A reading greater than 7 is alkaline, and below 7 is acidic.

TESTS IN REAL LIFE: Most of my plants tested the same, between 6 and 7.5, which is the ideal range for indoor plants. Again, I use this primarily for the moisture meter setting, so wasn't expecting amazing accuracy from this or the light settings. pH meters tend to be super expensive. Somewhat accurate, and good to alert you if your soil swings too far acidic or alkaline, which can turn nutrients toxic, but there's a reason pH meters cost far more than this meter so I wouldn't get this meter just for this setting. Have a look at the Bluelab pH pens instead.  

How does it work without batteries?

The meter works a bit like a battery without water. The 2 probes are 2 different types of metal. When you add an electrolyte (the moisture in the soil), it works like a weak battery, but with enough 'voltage' for the sensor to read. The less water in the soil the less voltage goes through the meter (so you'd get a reading on the moist to dry side). 

How accurate is it?

Think of this super-affordable tool as a peace-of-mind back-up for your own common sense to help you check down where you can't reach. Most plant parents get it for the moisture function. Keep in mind you can get WAY more expensive stand-alone light, pH and water meters so do keep your expectations in line with the price! See the 'tests in real life' for an idea of accuracy for each reading and have a read of How analog water meters work > to help you get the best results.

Can I leave it in the soil?

No, this type of water meter is the type you insert to get a reading, then remove and store in-between uses. For the type you leave in a plant that changes colour as the plant dries out, have a look at Sustee > instead. Leaving this type in the soil will erode the metal probes.

Please note

Plants, pots and other accessories shown in some photos not included. This soil tester does not come in a box. Have a look at the Good Clean Health 3-in-1 Soil Tester if you'd like one in a nice box with directions (that one's lovely to give as a gift).