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Bluelab MONGUA Guardian Monitor for pH, Temperature, and Conductivity (TDS) Measurements in Water with Easy Calibration, 3 in 1 Digital Nutrient Meter for Hydroponic System and Indoor Plant Grow White

4.4 4.4 out of 5 stars 733 ratings

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Guardian Monitor
  • Monitor pH up and down, temperature, nutrient (TDS) level in water to maximize your grow and ensure plants get a balanced feed; General uses includes growing tent and reservoir; Selectable conductivity units include TDS, EC, ppm 500, ppm 700 and CF
  • This hydroponics tester has ATC that provides consistent reading regardless of any fluctuations in temperature; High and low alarm when outside parameters, selectable units include TDS, EC, ppm 500, ppm 700 and CF
  • Lab quality glass pH probe with easy two point calibration; Conductivity / temperature probe comes factory calibrated so it's ready to be used; Double junction probe is more accurate than test strips and drops
  • Combine with Bluelab pen and meter for full garden nutrients monitoring in water and soil; Other features: International power supply, water resistant design; KIT INCLUDES: Calibration solution, EC probe and pH probe, probe care kit is sold separately
  • Made in New Zealand and manufactured by Bluelab, the industry leader in hydroponic testing equipment, built for growers; 2-Year Limited Warranty with proof of purchase (6-month warranty for pH probe)

Customer ratings by feature

Easy to use
3.9 3.9
Accuracy
3.5 3.5
Value for money
3.4 3.4

From the manufacturer

Bluelab Guardian Monitor provides 24/7 continuous monitoring of your key parameters

Bluelab MONGUA Guardian Monitor

The simplest and most effective reservoir monitor you could ever own

Key features include:
  • Plant-safe green LED displays
  • Simple push-button pH calibration system
  • No calibration required for conductivity and temperature
  • Water-resistant design
Customisable measurement scales for extra convenience

For utmost convenience, you'll be able to customise your Bluelab Guardian Monitor with your preferred measurement scales. Not only will the Guardian Monitor measure pH, but you can also select from EC, CF, PPM 500 (TDS) and PPM 700 for conductivity or from °C and °F for temperature.

Monitors pH, conductivity and temperature

Silent flashing high and low alarms

To start monitoring your reservoir, set your preferred ranges for pH, conductivity and temperature on your Bluelab Guardian Monitor. If the solution moves away from the ideal range, the display will alert you; just remember to set high and low alarms for your parameters. With one glance, you'll be able to check on the status of your reservoir.

New Zealand-made quality, built for growers

Our products are designed and built with growers, for growers - and our Bluelab Guardian Monitor is renowned as the simplest and most effective reservoir monitor. The Bluelab Guardian Monitor was designed and built in New Zealand.

Tried and trusted by growers like you

Bluelab PENPH pH Pen Calibration

Bluelab MONGUA Guardian Monitor settings

Bluelab MONGUA Guardian Monitor

Bluelab tick

Easy calibration for pH

Get rid of the headache of pH calibration with our simple two-point calibration process. Remember to calibrate your monitor's pH probe before first use. You do not need to calibrate for conductivity or temperature.

Automatic temperature compensation for accurate readings

Designed for indoor use, the Guardian Monitor can be mounted on a wall or hung on a support bar. Set up your reservoir and place the pH and conductivity probes in the solution. Our probes are fully temperature compensated, which means you'll be getting accurate readings every single time.

Superior design and manufacturing

All Bluelab products are proudly designed and manufactured in New Zealand. Our rigorous production process includes each monitor being inspected by hand before it finds its way to you!

The Bluelab promise

The Bluelab Guardian Monitor comes with reputable support. This means that you can have complete peace of mind when you invest in the Bluelab Guardian Monitor.

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pH Pen Conductivity Pen Grower's Toolbox Combo Meter Soil pH Pen Pro Controller
Customer Reviews
4.4 out of 5 stars
4,484
4.6 out of 5 stars
1,039
4.4 out of 5 stars
1,139
4.4 out of 5 stars
944
4.2 out of 5 stars
952
Accuracy 0.1 pH, 1°C/2°F 0.1 EC, 1 CF, 50 PPM (PPM 500 TDS), 70 PPM (PPM 700), 1°C/2°F Bluelab pH Pen: 0.1 pH, 1°C/2°F; Bluelab Conductivity Pen: 0.1 EC, 1 CF, 50 PPM (PPM 500 TDS), 70 PPM (PPM 700), 1°C/2°F 0.1 pH, 0.1 EC, 1 CF, 50 PPM (PPM 500 TDS), 70 PPM (PPM 700), 1°C/2°F 0.1 pH, 1°C/2°F 0.1 pH, 0.1 EC, 1 CF, 50 PPM (PPM 500 TDS), 70 PPM (PPM 700), 1°C/2°F
Parameters measured pH, temperature Conductivity/EC, temperature pH, conductivity/EC, temperature pH, conductivity/EC, temperature pH, temperature pH, conductivity/EC, temperature
Replaceable probe
Backlit screen
Power supply 1 x AAA alkaline battery 1 x AAA alkaline battery 1 x AAA alkaline battery per pen 2 x AAA alkaline batteries 1 x AAA alkaline battery Input: 100-240 Vac, 50-60 Hz, 5 VA, 4 interchangeable plug types (USA, Euro, UK, NZ/AUS) Output: 24VDC 0.4amp
Popular for Hydroponic nutrient availability measuring in solution Hydroponic nutrient density measuring Hydroponic nutrient solution measuring starter kit Powerful handheld nutrient solution measuring with probes capable of sitting in reservoir Hydroponic nutrient availability measuring in media Wall-mounted nutrient solution monitoring for medium to large reservoirs with alarm parameters and automated dosing (pumps sold separately
Bluelab Grower in Greenhouse

Bluelab: Trusted by growers like you for over 30 years

For over 30 years, Bluelab has been providing award-winning and innovative technology that helps growers unlock their plants' full potential. At Bluelab, we believe that our commitment to designing hardy, purpose-built products and creating strong educational programs will help elevate the standard of growing. Together with our growers, we will create a world with fewer pesticides, food miles and less water usage. Let Bluelab’s products take your growing to the next level.

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Product information

Warranty & Support

For warranty information about this product, please click here [PDF ]

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Bluelab

Bluelab MONGUA Guardian Monitor for pH, Temperature, and Conductivity (TDS) Measurements in Water with Easy Calibration, 3 in 1 Digital Nutrient Meter for Hydroponic System and Indoor Plant Grow White


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Product Description

n just one glance it clearly conveys all 3 critical parameters for successful growth: pH, conductivity AND temperature.

The Bluelab Guardian Monitor is a constant indicator of the desired levels of EC/ppm 700/TDS/CF, pH and temperature, enabling the grower to optimise these parameters as the crop progresses through each growing phase.

The Bluelab Guardian Monitor is mains powered and is mounted to the wall or hung on a support and the probes simply placed into the reservoir.

With the Bluelab Guardian Monitor monitoring your crops 24 hours a day and with the ability to set high and low alarms, a flashing display lets you know if one parameter moves away from the ideal, allowing you to make the required adjustments quickly and effectively.

Features
• Large easy to read displays
• No calibration required for conductivity and temperature
• Simple push button pH calibration
• Selectable values for conductivity and temperature
• Flashing high and low alarms
• Temperature compensation
• Greater tolerance to RF/electronic interference provided
• International power supply
• Replaceable double junction pH probe
• Adjustable display brightness
• Non-volatile memory

Probe Tips
All probes are interchangeable between all Bluelab productsProper hydration of ph probes is vital to maintain wick
All pH probes eventually need to be replaced—they can only house so much reference solution
KCl storage solution is required for optimum probe maintenance
RO water will reduce probe life

WARNING:

CHOKING HAZARD -- Small parts. Not for children under 3 yrs.

Customer reviews

4.4 out of 5 stars
4.4 out of 5
733 global ratings

Customers say

Customers like the quality and ease of use of the product. They mention it's a great meter and makes keeping solution easy to manage. That said, opinions are mixed on value, accuracy, and performance.

AI-generated from the text of customer reviews

39 customers mention28 positive11 negative

Customers like the quality of the product. They say it's an excellent meter, and the best on the market for constant display. Some say it is a perfect tool, and a sweet unit for a nutrient reservoir.

"This is such a sweet unit for a nutrient reservoir. Now i can just peek in and see that everything is perfect...." Read more

"This Bluelab Guardian Monitor is excellent. Everything was packaged well. pH probe had sufficient storage solution in it. Easy installation...." Read more

"...Same with ppm. Great device, when you can swing it - get it. Will not disappoint." Read more

"Item don’t work, came in a torn up box, was def used not brand new. The Ph pen was busted and had blue liquid in that’s it’s not suppose to have...." Read more

31 customers mention31 positive0 negative

Customers find the product easy to use. They say it makes keeping their solution easy to manage, and convenient to be able to check both at once. Customers also say it's easy to set up and accurate, and takes the hassle out of monitoring their system. They also say that it saves a ton of time.

"...hydroponics, especially DWC this product is a must very easy to set up through YouTube and works just like it says it does very happy I have this" Read more

"...I had been testing both manually daily. It is so much easier and more convenient to be able to check both at a glance...." Read more

"Guardian it is! Calibrate once a month and it keeps me dialed it at a glance, no more pens and samples.Update...." Read more

"...are a tad bit pricier than some but they work great and are very easy to calibrate...." Read more

4 customers mention4 positive0 negative

Customers are satisfied with the appearance of the outdoor living product. They mention that it looks good, is well designed, and has a nice, easily visible green light display.

"...Now i can just peek in and see that everything is perfect. Nice, easily visible, green light display...." Read more

"...stays calibrated very accurate runs on both 120 and 240 sturdy and well designed Would buy again for surehighly recomended over pens" Read more

"Works great and looks fancy to!" Read more

"looks good" Read more

39 customers mention18 positive21 negative

Customers are mixed about the performance of the meter. Some mention it works very well, is accurate, and easy to use, while others say it only worked for a short while and stopped functioning properly. Some customers also say it does not do a good job maintaining a proper PH level.

"Item don’t work, came in a torn up box, was def used not brand new. The Ph pen was busted and had blue liquid in that’s it’s not suppose to have...." Read more

"...They are a tad bit pricier than some but they work great and are very easy to calibrate...." Read more

"...My take is that the probe is no good. It hasn't been six months yet, and I need this now. I didn't think I would have this problem." Read more

"...Use induction.. and gavita pro 1000s ...and turn out was amazing due to guardian bluelab bc was able to check everything as nutes added and is..." Read more

33 customers mention17 positive16 negative

Customers are mixed about the accuracy of the product. Some mention that it's super accurate and easy to use, while others say that it doesn't calibrate, does not include calibration solution, and gives inaccurate readings.

"...The plants are telling me the readings are plenty accurate. This upgrade is worth every penny." Read more

"...with the calibration solution for the ph, but it did not include the EC calibration solution which is supposed to be included...." Read more

"This is easy to set up and accurate. This is the one you want to buy and should buy." Read more

"The probe has been in use for 1.5 months and now it won't calibrate. Cheapo pens last longer" Read more

19 customers mention12 positive7 negative

Customers are mixed about the value of the outdoor living product. Some mention it's worth the price, while others say it'd be better off with a handheld device.

"...This upgrade is worth every penny." Read more

"...It was somewhat expensive for monitoring a single tower, but I have no regrets given how much time I save in manual testing." Read more

"...The handheld ones are certainly cheaper and it might make justifiying this guy hard...." Read more

"Love this thing its defiantly worth the money, Only thing is I wish I got the upgrade to Wifi. But it was almost $ 150.00 more...." Read more

4 customers mention0 positive4 negative

Customers are disappointed with the missing pieces of the outdoor living set.

"...First time I recieved a used unit that was missing some parts, but after contacting hydrofarm they replaced the item very fast without any hassle...." Read more

"Missing parts..." Read more

"Missing parts..." Read more

"Missing parts..." Read more

Works well so far.
3 Stars
Works well so far.
The box says it has a six month warranty on the ph probe, but when I connected the ph probe, it ph at 4.5 and 6.5 with the bluelab and Apera ph. I then placed the probe in the solution, and it came back 3.6 and 6.6.My take is that the probe is no good. It hasn't been six months yet, and I need this now. I didn't think I would have this problem.
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Reviewed in the United States on September 3, 2023
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Reviewed in the United States on July 25, 2022
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Reviewed in the United States on March 30, 2023
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Reviewed in the United States on June 18, 2022
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Reviewed in the United States on March 7, 2024
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Reviewed in the United States on September 21, 2020
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Reviewed in the United States on March 27, 2020
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Reviewed in the United States on June 20, 2016
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Vicky
5.0 out of 5 stars Super
Reviewed in Canada on November 8, 2023
Style: Guardian MonitorVerified Purchase
S radford
5.0 out of 5 stars It's spot on
Reviewed in the United Kingdom on January 14, 2024
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Brandon
5.0 out of 5 stars Quality brand name.
Reviewed in Canada on January 9, 2021
Style: Guardian Monitor ConnectVerified Purchase
One person found this helpful
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Sayo86
5.0 out of 5 stars Il miglior acquisto
Reviewed in Italy on November 18, 2022
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Loris
5.0 out of 5 stars Top
Reviewed in France on July 4, 2022
Style: Guardian MonitorVerified Purchase