Quantum PAR Meter Full-Spectrum High Precision PPFD Tester for Photosynthetic Activity of Indoor and Outdoor Plants 400-700nm Light Lux Tester

It's not the professional version that you see Hollywood producers carrying. I don't need all that. I just want basic readings from LED lights for plant growth factors. For that it does quite well. I've messed around with it using sunshine as well. It seems pretty accurate. Full mid day summer sun should max it out. It does. Evening sun, even though it seems 'weak' to our eyes, is still magnitudes brighter than most commercial LED plant lights. You can measure it yourself, with this meter. I can't vouch for the exact accuracy but it will certainly give you a proper idea of what you are working with. I used it to dial in my sprout dome and grow tent. Too much light makes the baby go blind, so to speak. Read the charts and figure out how much light is good for your plants.

A PAR meter is useful to know if plants are receiving enough light of the kind that they need. Using this has been very useful for adjusting grow lights and understanding when a grow light is needed. I am completely reliant on the claims of accuracy since I don't own an apogee meter to test it against. Maybe someone does and can report the results. But I'm happy with it and do recommend it if you aren't sure that your plants are getting enough light, or you are not getting the results you want with the lights you have. Use the PAR reading along with DLI (daily light integral) to adjust your light intensity or distance to your plants and how many hours the light must run for the plants you are growing. Different plants need different total amounts of usable light. There are websites and videos that cover PAR and DLI which are a good resource. Addendum: This is really intended for use with indoor or greenhouse lighting, not for outdoor use. It works fine outdoors, but outdoor light is very strong and there is seldom any need to measure that. This is very useful when growing or starting plants indoors, even in a greenhouse. Plants need a certain total amount of light each day. The PAR meter measures the INTENSITY of the light spectrum that is usable by plants. Intensity is one part of the equation. The other part is QUANTITY needed which is measured by DLI (daily light interval). That varies depending on the type of plant and even its stage of growth, if you want optimal results. Think of your plants needing a certain quantity of daily light. PAR indicates how fast the light is coming in, DLI shows the total amount of light needed. PAR x Hours of light = Quantity (DLI). Knowing the PAR allows you to calculate the number of hours that grow lights must be on to get the necessary DLI. I start plants early in the year in my starter greenhouse. The days are short so I must supplement the natural light with grow lights. Usually a PAR of 700 - 750 is sufficient for most plants over about 16 hours. During the day, natural light supplies a good portion, so I use a timer to turn the grow lights on early in the morning when it is dark, then off once the sun is strong enough, then back on in the afternoon as the sun dims, and then off for the day late at night. If you are growing indoors, then the lights would be on from early morning to late at night. A PAR meter is crucial to properly adjust your lighting. A PAR meter will quickly show the insufficiency of light coming in through a window for most plants.

This meter is great. Perfect for checking light levels for your plants inside and out. Some of your LED lights will show you the levels 1 ft, 2 ft and 3 ft away. Most don’t because their lights are below minimum requirements even at 1 ft! Excellent quality and easy to use even for an old plant lady. Don’t tell me you have good light - show me your numbers!

This instrument is a must have for optimum growing- Accurate and Quality

Works great but I’d get one with a corded transducer next time.

Takes time for a new comer to figure out how to read. Bought for my orchids when realized they are not doing well due to no light. So bought grow lights and this PAR LIGHT METER. After much research found best to buy are the PAR meters. But not spending $150. This was recommended as part of best to buy. Then researched foot candle conversion. So this comes umol/m1/s. Multiply 1um= 4.55 foot candles. You need 200-400 FC TO GROWN AN ORCHID. I RESEARCHED OVER A WEEK AS no pertinent information on conversion, Foot candles, PPFD,are on the info for the product. You have to do the research so good luck. After I figured all this out not knowing anything about light meters it works great now. Used ALEXA for researching grow lights and light meters. she was great knew I bought a light meter for use with orchids. 53.31um gives me the 245 fc I want. No where could I find what the how much um I needs. All very confusing. Hope this doesn’t confuse you more or helps you save time. I bought this primarily for orchis

Slightly pricey but gives you data you can see real growth on. I use these to dial in my Vivosun grow lights to make sure my seedlings and more mature plants are getting appropriate light intensity. This was my first year using the product and I do feel like I had less instances of leave burn from too much light and legginess from too little. Overall, the unit is small and easy to use. Very easy to read numbers and also has a hold function. Would recommend this to the avid indoor germination gardener but not just a hobbyist.

Good quality

Funktioniert extrem präzise und zeigt mir genau an ob alles stimmt oder nicht, bin sehr glücklich dass ich mich nicht mehr auf das dämliche Handy verlassen muss wo die Werte sowieso kaum stimmen wenn man nicht eine entsprechende teure Kamera hat.

Very good.

Pratique, fiable et pas trop cher !

Indispensabile per non improvvisare

Works good