Ppfd meter - UNI-T UT383 Mini Digital

100 bucks on Amazon right now for a decent Korean meter. I've had the same one for a couple of years, and it works very well for the little I use it, it's perfect light intensity every time, no more guessing. Time it has saved me in scribbled notepad calculations alone makes it worthwhile. Time is money, 100 is worth X many hours of my time. If you plan on growing long-term it's a very good investment. Best of luck in your search.

Hi bud. Dunno about that digital meter specifically, but watch out in general. Alot of these meters aren't built to factor in blue and red led lights, hence a lot do not give accurate readings. I've been holding off with several purchases because of this issue. Hope this helps, even just a little.

Ive use a quantum par senor by photom it was nice. https://www.amazon.ca/PHOTOBIO-LGBQM2-Advanced-Quantum-Micromols/dp/B08HPGLZHL I did not calbrate my phones app though and should have.

Yeah, using the ut383, multiplying the lux reading based off migro numbers 0.017 for red and white for my light, plants are always happy now.

Max DLI is not a static value... it is relative to atmospheric CO2, temperature and relative humidity. So, it will be slightly different for you then the next person. You can't just target a certain DLI and not do anything else. No matter what deveice you use, it will require some trial and error after the fact -- observe the plant and adjust power or hanging distance. a quantum metere may have less trial and error, but that's a 1-off context. After the first time you find that goldilocks zone, all you have to do is match the klux values in future for same DLI as you learned to provide this time - no different than the quantum meter in this regard.. Whether you use a lux meter or a phone app converting lux to PPF does not matter. Both can achieve the same thing as far as leveling out the intensity of light across the canopy. PPFD is not a single location measurement. You must measure PPF all over the place equidistant apart and same distance from light. take that average and you have PPFD. For this, you do need a proper quantum meter , but again, it doesn't really do you any good. you can measure in klux and make sure you hit similar values in future for similar results in the exact same way. Knowing the exact DLI is irrelevant because the plant and environment dictates what you can give and it varies garden to garden, season to season. Whether you use the photone app or a klux app, it really doesn't matter. The phone is converting lux to ppf. This is not a one-size-fits-all conversion factor, so the potential for error is fairly high.