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5 Best PAR Meters for Growing Cannabis 2021 – Reviews & Top Picks

Last updated: April 8, 2021

Digital Light Meter-BTMeter-BT-881D-Amazon

LED’s offer a wide range of light colors for plants, but it also comes with a lot of fiddly guesswork without a proper PAR Meter. It’s a lot of stressful effort to make sure an LED is adjusted to the perfect light temperature for different stages of plant growth, and there’s no way to be sure simply by eyeballing it.

Proper use of the light spectrum available can take a mediocre grow to a great one with the right adjustments, which is made more important by the limited light that LEDs give off. A good PAR Meter is a nice tool to have for any grower using LEDs, however, the investment can seem to be a bit much for low-budget growers.

We’ve taken a look at the current offerings online and created a few reviews to try and find the best PAR Meters for all types of Cannabis growers.

A Quick Comparison of Our Favorites

Image Product Details
Best Overall
Winner
Hydrofarm LGBQM Quantum PAR Meter Hydrofarm LGBQM Quantum PAR Meter
  • Measures a huge range of light spectrums
  • Included software helps with organization
  • Great price point
  • Best Value
    Second place
    BTMETER BT-881D PAR Light Meter BTMETER BT-881D PAR Light Meter
  • Accurate
  • Really good price
  • Will last awhile
  • Premium Choice
    Third place
    Apogee MQ-200 PAR Meter Apogee MQ-200 PAR Meter
  • Accurate
  • Wide range of light sensors
  • Very durable
  • Dr.meter Professional LED Light Meter Dr.meter Professional LED Light Meter
  • Very accurate
  • Top-tier build quality
  • Sun System 748205 PAR Meter w/ Remote Sensor Sun System 748205 PAR Meter w/ Remote Sensor
  • Remote sensor
  • The 5 Best PAR Meters for Growing Cannabis – Reviews 2021

    1. Hydrofarm LGBQM Quantum PAR Meter – Best Overall

    Hydrofarm LGBQM Quantum PAR Meter

    A full functional PAR Meter at a great price, the Hydrofarm LGBQM Quantum is the kind of product we were looking for when starting this list, and are very glad to have found a recommendation most might overlook.

    This meter offers measurements for the full range of non-visible and visible light that plants can photosynthesize as well as logging software for a PC to keep track of measurements easily. It was also built with LED reading in mind, making it perfect for growers who are trying to optimize their low-power LED growing periods.

    The cheap price of the Hydrofarm LGBQM product comes with issues in structural quality. We were able to fix this when one of the connectors broke after about six months with a bit of hot glue. This being said, it lasted long enough to get readings for the LEDs we were working with over the course of two grows. Meaning we were able to figure out the LEDs settings, keep them logged, and had little use for the PAR meter at that point anyhow.

    Hydrofarm’s product is functional, and at a great price point which makes it a truly great choice for low-budget growers who want to get the most out of their LEDs. Don’t rely on it lasting for years and years though, so keep all measurements recorded along with the light’s settings just in case.

    Pros
    • Measures a huge range of light spectrums
    • Great price point
    • Included software helps with organization
    Cons
    • Build quality leaves a lot to be desired

    2. BTMETER BT-881D PAR Light Meter – Best Value

    BTMETER BT-881D PAR Light Meter

    BTMETER is offering a quality-built product, but lacking in measurement capabilities when compared to our previous options. This is technically a LUX meter, meaning it is measuring a visible light spectrum, leaving the user to extrapolate extra information themselves.

    Ballparking the radiance is possible with this, but completely accurate measurements in the non-visible spectrums will leave a lot to be desired. It’s a decent product for a low-price and can still help figure out where the strongest light is in a room and which parts of a plant need more light hitting them. The BTMETER BT881D is the best PAR meter for growing cannabis for the money, at least when measuring light intensity.

    This is more about figuring out intensities than specific light spectrums, which is still a very useful tool to have around.

    Pros
    • Accurate
    • Really good price
    • Will last awhile
    Cons
    • Can’t measure non-visible light
    • Technically a LUX meter

    3. Apogee MQ-200 PAR Meter – Premium Choice

    Apogee MQ-200 PAR Meter

    The Apogee MQ-200 is an ideal product for when the budget isn’t a concern and accurate light measurements in any environment is a must. It’s another under-the-radar product, but it’s basically the perfect choice for setups that are trying to pinpoint the perfect light spectrum.

    Measurements are accurate and offer a wide range and it’s a structurally sound product that even works underwater. This will also last and last, so in cases where a PAR Meter is going to be useful more than a few times, the price increase will eventually pay for itself.

    Compared to the last two products, the Apogee has a pretty big price bump but it’s also not the most expensive thing on the market. It’s a very worthwhile product for cannabis growers who are trying to take their light spectrum management to the next level.

    Pros
    • Accurate
    • Wide range of light sensors
    • Very durable
    Cons
    • Pricey
    • Overkill for low-budget grows

    4. Dr.meter Professional LED Light Meter

    Dr.meter Professional LED Light Meter

    Another product mostly meant for visible light measurements, but it can still find a use for growers looking for a premium LUX meter. Like the BTMETER BT-881D PAR Light Meter, the Dr.meter Professional will not measure things outside of the visible spectrum. However, it does offer incredibly accurate measurements for the amount of visible light hitting an area, and the exact spectrum it’s measuring.

    The build quality is great, and it comes in a very easy to use hand-held device. Ideal for spot-checking hot and cold light spots to make sure every part of a plant is getting enough light. It’s ideal for growers looking to pinpoint the hot and cold spots around the room for lighting, and it actually is pretty great at it.

    The Dr.meter is of the more accurate LUX meters we’ve ever had, and works right out of the box with very little calibration. It sits lower on the list because it’s a bit overkill for the needs of the average grower, but if you like photography, it might actually be a great purchase.

    Pros
    • Very accurate
    • Top-tier build quality
    Cons
    • LUX meter
    • Won’t measure non-visible light

    5. Sun System 748205 PAR Meter w/ Remote Sensor

    Sun System 748205 PAR Meter w: Remote Sensor

    Rounding out the list, this Sun System PAR Meter offers a wide spectrum of measurements and an accompanying remote sensor. The remote sensor can help growers, who take the same measurements again and again, not have to set the system up every time they need to take a measurement. Simply stick it where it needs to be and get accurate results at any time.

    The Sun System unit hits the bottom of the list due to it being slightly less accurate than our number 3 slot, while also being at a similar price point. It also just didn’t feel as sturdy as we wanted it to be. It feels like some skimping happened in the factor in exchange for the fancy remote sensor.

    Yes, the remote sensor is pretty cool and the measurements are still reliable, but if we’re paying a premium, we want a product that measures like one.

    Pros
    • Remote sensor
    Cons
    • Measurements can be a bit off
    • High price point
    • Build quality leaves some to be desired

    Buyer’s Guide

    After going through all these products, there were quite a few things we had to stay on the lookout for when determining what would make this list.

    The difference between a grow that’s optimized with good meters and just setting it up via the eyesight of the grower is actually quite big. The density of cannabis relies on good light penetration past the top canopy, and it is difficult to get without a bit of extra information just out of the reach of our eyes.

    But, figuring out whether it is worth the extra price and effort is going to vary on the grower and the setup of the room. We’ve tried to consider a lot of perspectives when making this list, and reasoned out the best purchases for all types of growers through multiple different factors.

    Accuracy

    Missing a reading and logging it can have a major impact on future grows, meaning the accuracy of the meter matters a ton. A bad meter can be the source of a lot of woe going into the future, and it’s pretty hard to pinpoint the cause after using the readings for a long time.

    We understand that this is an additional accessory for growing, thus if money is going into it then light consistency is a concern and we need to be doubly sure that the product will do what is needed.

    Anything more than a 10% deviation from a light source that we knew the reading of beforehand was considered inaccurate. There will always be a bit of variance between sensors, but once getting into the double digits the reliability needs to get called out.

    Anything beyond 15% didn’t make the list, just because it’s mostly useless at that point for any kind of reading.

    PAR vs LUX

    We also need to decide what is worth knowing for a good growth. PAR meters measure out light past the visible range, but within the range that plants can photosynthesis. This photosynthetic radiation is what most growers are trying to figure out when optimizing a grow with a PAR meter.

    PAR is ideal but comes at a premium. In a lot of cases, knowing the entire spectrum of light isn’t as important as being able to pinpoint the amount of light hitting certain parts of a plant. Seeing if the light penetration through the canopy is hitting the branches below is a great way to figure out where to trim plants at, or if it needs to be adjusted to allow that secondary layer to develop more.

    LUX meters are a solid choice for this and are much cheaper than a fully functional PAR system. For budget grows, a LUX meter is a solid consideration.

    Durability

    Using a meter that doesn’t have the structural quality to last for more than a few months of heavy is not ideal, but that doesn’t mean it is worthless, either. Once the readings of an LED are honed in and recorded, a PAR meter doesn’t have much use until the lights start aging out or a new system is installed.

    Furthermore, they aren’t really an object that tends to see a lot of wear and tear. It is used a lot initially for readings, but with gentle care even a flimsy piece of plastic isn’t just going to fall apart on its own.

    Paying a premium for a product that is going to sit in a drawer after its initial job is done seems like a waste of money in these cases, so a stronger emphasis was put on accuracy and price point vs simply structural durability.

    Ease of Use

    Though growing cannabis requires the grower to sort of become an expert on lighting anyways, there’s a bit more to using something like a PAR meter to get accurate measurements. Certain products require pretty advanced knowledge of mathematical formulae or have arcane settings that need to be enacted to get accurate results.

    Because of this, we put an emphasis on products that are more set up and go, versus having to read a book about the functionality of the meter. That doesn’t mean they don’t require some understanding, just not an advanced degree. On the other hand, more readings can mean more accurate results. A super simple device that doesn’t give exact information may as well be as good as your own eyes.

    There’s a balance to be struck here, between that of a lighting professional and going in completely blind and trying to find that middle ground is the goal for PAR meter use for a grow op.

    Price

    We had to look at what we got for the money when considering this aspect of PAR meters. It’s an expensive tool, but a very helpful one in the right hands.

    A lot of PAR meters that are cheap don’t really have the accuracy of more expensive ones, that’s why the Hydrofarm LGBQM Quantum PAR Meter caught us so off-guard. Accuracy at a low price is quite difficult to find. Looking at the price on a per-grow basis, we wanted to be sure that the amount of money spent with have lasting effects on any future grows as well.

    Ideally, the price points of these meters should pay for themselves over time via better results in growth due to the increased information of the light being used. This is also why we didn’t recommend the most expensive products on the market throughout this list, as there’s a bit of a wall wherein the extraneous information, that pricier models offer, doesn’t do much for us.

    Need

    Purchasing a PAR or a LUX meter sometimes comes down to more than just what the budget allows. A good PAR meter is absolutely needed to completely optimize a grow room, and this can be extra important in low-budget grows with smaller lighting systems.

    Using one of these devices can actually end up saving a fair bit of money for a savvy grower, as it can help rearrange a room in a way that more plants can thrive in a space that was once seen as too small. LEDs can be a bit tricky when eyeballing the light spread in the room, as the diodes are producing a lot of wavelengths we cannot see. Being able to organize this better and know where the best light is almost always can improve any grow.

    However, it will not replace other more essential parts of a grow and shouldn’t be seen as mandatory when compared to better quality lights.


    Conclusion

    Depending on the individual grower’s needs, there are a couple of products here we’re going to be recommending.

    First off, that Hydrofarm LGBQM Quantum PAR Meter is a really good price for a full-functional PAR. Though build quality is lacking, it will last long enough to log the exact measurements of an LED over the course of a grow or two. It might even last longer if care is taken with it, or some DIY repair work is done. Price-wise and accuracy, it’s really hard to beat.

    Secondly, the BTMETER BT-881D PAR Light Meter is the choice for those who don’t need to know the precise radiance of light, but just need to figure out the amount of light hitting certain areas of a room. It’s not a major purchase price-wise, but it is accurate at what it does and is very easy to use. It’s not a replacement for a PAR, by any means, but it does a great job at light intensities.

    We hope getting these reviews out here helps some growers figure out the mess that is the PAR meter market.


    Featured Image: Digital Light Meter/BTMeter/BT-881D, Amazon