Measuring Equipment

To take control of your cannabis grow, you need to be able to take certain measurements! Here we provide our recommendations for all the different types of measuring devices for growing cannabis indoors. We include the hygrometers, pH meter, EC/PPM meter, LUX meter, and Scale that we use in our cannabis grows! Take control of your grow and get the right equipment to measure Temperature, Relative Humidity (RH), pH, Electrical Conductivity (EC), Light, and the weight of your harvest!

Thermometers & Hygrometers

Ambient Weather WS-10
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This weather station system is unmatched for complete environment metering. It has Radio Frequency remote sensors and is capable of monitoring up to 8 receivers. You can place the main display anyplace that it is convenient and monitor the heat and humidity at several places inside your grow space. This is a very powerful climate monitoring tool suitable for any size grow!

Hygrometers with Probe
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For a somewhat less expensive option, we recommend getting a hygrometer with a wired probe that can measure the temperature and humidity inside the grow space. You can mount the unit outside the tent and run the probe into the tent through a port. I have two similar hygrometers and use them in different ways on every grow.

Be aware, many similar units have a wired probe that only measures temperature. They may appear to measure both temperature and humidity, but they measure humidity at the base station not with the probe. The units that we recommend here all measure both Temperature and Humidity with probes.

Mini Hygrometers

Mini hygrometers are particularly useful for curing because they can easily fit inside the jar with your buds. They also come in handy for seedlings in humidity domes.

Caliber IV
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The Caliber IV hygrometer is unmatched in accuracy for drying/curing measurement. Dr. Photon and I both use the Caliber IV. However, it is not easily available in the UK or Canada.

Inkbird ITH-10
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This is another excellent option for a mini hygrometer. It is more widely available and less expensive than the Caliber IV. Both of these models are far superior to cheaper digital or analog hygrometers.

pH Meter

The technology involved in measuring pH is sensitive and sophisticated. There are numerous cheap pH meters on the market, but these are shortlived and unreliable. You do not need the most expensive models, but it is worth investing in a quality pH meter. 

Apera Instruments pH20
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Dr Photon and I both use and recommend this Apera Instruments pH meter. It is easy to use, reliable and accurate. I have owned it for a year now and it has proven very consistent and rarely needs calibration. It also comes with small jars of calibration fluid, rather than powder. It is a great balance of quality and price for a pH meter for home cannabis grows!

pH Calibration Solution
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All pH meters require calibration eventually. The Apera unit that we recommend above comes with small bottles of calibration fluid that will get you through a grow or more. Other meters come with powders which are very difficult to mix. Rather than using the powders or using an inaccurate meter, get some pH calibration Fluid and learn how to keep your meter tuned up.

Electrical Conductivity (EC)

Measuring Electrical Conductivity (EC) is absolutely critical to managing your fertigation strategy and nutrient solution strength. The technology involved in measuring EC is rather simple which means that you do not need to invest in an expensive meter. However, if you use one of these meters, the water should be measured at about the same temperature that it is applied to the plants (about 68f/20c).

EC/PPM meter
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The meter that I use is pictured and linked for the US amazon. I have verified its accuracy against other meters and it has served me well for more than 5 grows. The UK and Canadian options are similar models sold under different brands.

Measuring Nutrients

10ml Oral Syringes
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I honestly believe that there is no better way to measure and mix nutrients than with using small oral syringes. I assign one syringe to each nutrient product and I Velcro the syringes directly to the bottles. These syringes measure in milliliters and teaspoons and it is easy to measure fractions of a milliliter. The US and UK sets comes with 10 syringes. The Canadian options are a little odd, but the best deal is an 8-pack of curved tip syringes, which is what we linked. For any grower who is mixing nutes, these are a must buy!

Light Meters

Light meters are used to evaluate the light distribution in the grow space and to determine the best height to hang your light above the canopy. This is not a required tool. Many growers can do fine following general guidelines, but if you want to dial in your grow you need to be able to measure the light.

Lux Meter
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If you have HID lights or LEDs that produce a "near neutral", "warm", or "cool" balanced spectrum, then you can comfortably use LUX meters with acceptable reliability. The Dr. Meter Lux meter, which is pictured and linked, is a great value.

PAR Meter
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PAR stands for Photosynthetically Active Radiation. It is the amount of energy that the plants can actually use. This is the number you are really interested in when it comes to light. PAR meters can be used to measure any light source. They are the only option to measure monochomatic or "blurple" LED lights. However, PAR meters are much more expensive than LUX meters.

Scale

This is not required, but you are going to want to know how much you harvested!

Ohaus CL201 Compact Scale
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I wanted a good way to accurately measure and split up my harvest. There are many options in the hundreds of dollars, and then there are cheap kitchen scales. I wanted something in the middle! Our community member @Rosettastoned recommended this Ohaus Scale and I purchased it for myself (Dr Coco). It has a capacity of 200g, is accurate to the tenth of a gram and easy to use. I really like and recommend it!

About Our Product Recommendations

At Coco for Cannabis, our mission is to help growers maximize the success of their cannabis crops by providing scientifically accurate information and sharing proven growing practices.

The products that we recommend are the actual products that we chose to purchase and use ourselves. In a few cases, we recommend products that we would buy if we needed them. We do not accept advertising and will not recommend any product that we would not buy for ourselves. We offer this guide as a resource to growers.

We may receive a referral when you purchase products through this page. This is the main revenue stream that keeps Coco for Cannabis up and running! When you click through our links and make purchases you are supporting our work! As an Amazon Associate, we earn from qualifying purchases.

Whether we receive a referral does not influence our recommendations. For example, when products are cheaper to buy locally, we’ll tell you that rather than just recommend a more expensive online option.

Disclaimer:

The information on cocoforcannabis.com should not be considered as financial, legal, or medical advice. You are responsible for knowing and following the local laws that pertain to cannabis cultivation, possession, and use. Decisions to grow cannabis should be made in consultation with a lawyer or qualified legal advisor. Decisions to use cannabis should be made in consultation with your doctor or medical professional.