The Apogee Instruments MQ-500 Full Spectrum Quantum Meter, Accurate for All Light Sources Including LED, Lightweight, Waterproof Sensor, Long Warranty. Made in Logan Utah by Apogee.

I waffled for a long time about spending over $500 for a PAR meter, but I am glad I finally did. Yes it's a bit pricey, but if you want to maximize your growth potential and yield, this is a must have in my opinion. Until now I was merely guessing about the height to place my lights and just going by the manufacturer's recommendations. It is nice to finally know for sure what level of light (PPFD) my plants our getting.This unit is very well made and easy to use. I did not buy the extender wand, but plan to fashion one. Even though I can hold the sensor under the plants easy enough, I see now it will be easier to take readings being able to hold then sensor with an extender of some kind. Especially as the plants grow and get spaced further apart in my grow room. I don't use the storage function the unit provides, so I can't comment on that, but I might use it in the future and if I do I will edit this review.My only real complaint is it did not come with a pouch for storing the unit. At this price point I would think a nice leather carrying case would be included or any kind of carrying case for that matter. I will find something to server as one although the box it comes in works okay. It still gets a five star rating though as it's easy to use and tells me a lot about the light placement and quality of the light I am providing for my plants versus guessing.I can definitely recommend this for anyone wanting to measure PAR values which is a must for users of LED lighting and serious indoor growers.SOME DETAILSIf you want to read a little more about what I found after testing with this meter you can read on.I found out a couple of things real quick. For one the output of the inexpensive Chinese made lights I have purchased are way over rated by the manufacturer. They are 1500 watt rated lights, which is a common wattage chosen for indoor grows. They have a Veg and Flower switch which is also common. When set to Veg only, which is what I used on my first two grows during the Veg phase, the light output from 15-20 inches is less than 150-100 PPFD. Way below the 400-600 which is recommended. When I add the Bloom setting it gets to a respectable 450 - 550 PPFD. So I am now vegging with both switches on.The other thing I noted is the extent of coverage, again it is not even close to what the manufacturer shows in their charts, dropping off much more significantly toward then edges of the coverage range than advertised. However, using the meter I was able to confirm the effectiveness of reflective paint (flat white) on the walls which does greatly enhance the PPFD extending the light's effective coverage. I have a large grow room not a tent, so the plants closest to the walls get more of the reflective effect. Ultimately I plan to provide more light using some higher end LEDs so this will not be an issue in the future. More on that later.I still need to play around with the heights and positions a bit, but suffice is to say, on my last two grows (my 1st and 2nd indoor) my plants were not getting anywhere near the light levels needed for maximum growth and yield. I did surprisingly well though so I am excited to see the results on my next grow which has just started. Of course I will need more and different lights, as the ones I have will fall far short of the levels needed in the flowering phase (where 600-900 PPFD is recommended) unless I put them real close where there is a chance of burning the tops.In the end, I spent a lot of money on some cheap LEDs based on reviews and no real data. I was told this might be an issue by an expert grower. I won't mention his name here, but if you look at my profile I follow him on Amazon. As I am about to purchase some new higher end LEDs the information I gathered using this meter has really helped me make a more informed decision.I am going to start moving to quantum board LEDs and just purchased a Mars Hydro TSL 2000W and plan to purchase some even higher end US made NextLights down the road a bit. Do you need to spend this kind cash to grow a decent crop? No you don't. I did it with the LEDs I had that were only $15Oea. However, in the end and lesson learned, if you really want to maximize the potential of your grows, you need the right equipment and, unfortunately, you need to spend some money to get it. Including a $550 PAR meter.The End

I was hesitant too. Did a deep dive into all the information about PAR. Realized I needed a meter. Read all the reviews. I made the right choice for my purpose with this unit. It’s sturdy, seems tough, compact and well made also very easy to use. Very capable, keeps readings and can be downloaded with the sold separately proprietary cord you’ll need. If you’re serious, get this meter. It showed me a big mistake I was making. Helped me set lights correctly, which completely changed growth to phenomenal...

I've had this for a while now. very useful for adjusting your grow room LEDs especially any more,as the quality of some LEDlights have come a long way.in the current age of buyingChinese.Their burplelites,so to speak aren't the only option out there especially since they are basically a joke. Oops sorry getting off topic.the meter is valuable because with good old made in the USA LEDs you can actually dim them down because they're so tuned to best spectrums you save substantial money in electricity. I know my lights that I bought from Forever Green Gardens are so powerful that they need to dimmed because the plants grow so fast I almost can't lift the light up fast enough

Works as expected. I could not trust anything else.

Very nice light meter,top of the line and worth every penny. It's easy to use,reliable and accurate. Very happy with this purchase.

I’m running LEDs, so I decided to purchase this product, and I’m glad I did. LEDs are powerful, so I needed to know the exact distance from fixture to the canopy. No white tips, and more yield.

Hi,I've been looking forward to buying / receiving this Apogee PAR meter (light meter) for a long time. I'm a big fan of Dr. Bruce Bugbee. Suffice to say, I'm deeply disappointed because this device doesn't work. The battery provide is in discontinued packaging, the device's battery 'slot' is a joke, and when you pay nearly $600 dollars, you want what you paid for to work. I really wished it would've worked because I could overlook the cheapness of the device. It's like someone bought things up from the defunct Radio Shack and cobbled this thing together. A little extra effort in product production, design, packaging, instructions, and making sure the battery included was fresh (and not an old, left over Swiss battery, since this device is supposedly made in the USA) would go a long way.I look forward to very few things because life is life., and this Apogee product this out. Reviews, research, and endorsement videos... I'm a sucker that paid nearly $600 dollars for a box.

Bruce Bugbee is a beautiful man. The Apogee MQ500 is great. You can’t manage what you don’t measure. This is the mother of all measuring tools for PAR. I bought the extended range also as I added some non PAR lights. I wish i just bought that first, but it’s also nice to measure the deltas and know the distinct values for each. Easy to use and accurate. I added the wand and the case.