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

Been growing for years without a PAR meter. Tried a light meter once - but it was useless. Anyway, I switched to LED lighting this year - and being a noob to LED lighting, I bought this PAR meter. And it turns out it's useful ... Because .... It's consistent. It's accurate. It's easy to use. Let's me maximize the lighting without enduring any light burn. Let's me use the dimmers accurately. Turns the art of lighting into a science. This one's rugged too - been knocked around a bit now. Still works like new. Also has a record feature - which I've used twice so far. Might use it again - dunno yet. What I use all the time are the max and avg PAR features.

The media could not be loaded. I’ve been gardening for a while and tried a few different PAR meters. If you’re not gonna spring for an Apogee it’s a struggle to find one that works well. I have the photone app with extra diffuser and another cheap one that I bought on here and neither worked for me. This one is not expensive, but 80 bucks isn’t cheap either. Trust me, if it didn’t work, it was going back, but to my surprise, it’s awesome. Super accurate! The LED that I use has a published PAR map and that’s what I’ve used on all the meters I’ve tested. This is the first one that matches with The Light supposed to be putting out almost exactly from corner to corner. Great Job!

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.

I’m a second year cut flower farmer and I am starting soil blocks indoors from February through July. I bought this meter so that I could ensure my seedlings were receiving the correct intensity of light. Very easy to use and helped me set all of my grow lights to the proper heights.

I recently purchased the PAR meter, and I must say, it has been a fantastic addition to my gardening toolkit! As someone who is serious about growing plants indoors and optimizing their light conditions, this meter is a game-changer. I wouldn't say it is completely accurate, so unless you want to spend hundreds of dollars on a more advanced meter, definitely continue to monitor your plants; otherwise, this is a great choice for the price.

The is thing is more accurate than any hobby grower would ever need. PPFD readings are within 1 significant digit of my friends much more expensive quantum sensor and a 0.1 margin of error for 10x less is quite a deal. Can’t speak to longevity but I’m impressed with the price and initial performance.

This is a must have for any indoor grower. Similar to other reviewers I was scared off by the price of similar more advanced PAR meters but wanted something to measure the amount of energy my plants were getting at various distances from my light and also the strength of my light (e.g. 40% power vs say 100% power - turned up fully) this helped me dial in my lighting needs based on growth stage as to not over expose young plants and underexpose flowering plants. If you find what I’m saying confusing consult some of the experts on YouTube about DLI and optimal PAR for different growth stages.I was merely guessing or left to use light manufacturers PAR map as a general guide to figure out lighting needs (very inadequate) Once I got this it took all the guesswork out of the equation and help me dial in my lighting to EXACTLY what I needed. Very satisfied so far…

Very affordable PAR meter. It has really helped with my grow light area as well as my outside cacti and succulents. Easy to use!