Thank you Paul! Great question too, 12-14 hours of light is generally a good range for to aim for with Nepenethes. Something we need to add to this article is that 10-12 hours is still the minimum length of time you’ll want to have the light on depending on the plant. Plants fall into one of three categories; long-day, short-day, or day-neutral where the length of time, despite the Moles, can determine whether the plant goes dormant or not (day-neutral plants are unaffected). This is called Photoperiodism and the 10-12 hour marks are typically where the response is induced.

Hi Jakob, I think you bring up some great points, thanks so much for taking the time to comment!

While PPF is a more equivalent measurement to Lumens, manufacturers seem to provide PPFD more frequently than PPF so we wanted to make sure the calculators were geared toward PPFD entries.

Thank you for pointing out our error in the definition for efficacy! It is corrected.

It is true that an average PPFD would be most equivalent to LUX. However, we felt it would be best to leave it up to the individual grower as to whether they would like to average PPFD numbers or use hotspot and/or weaker readings for the calculations based on their needs. An average PPFD might be better for a larger plant that will take up more of the footprint while individual readings can be more beneficial for smaller plants based on where they will sit under the light.

your problem is the missing PPF (or at least a ppfd map)
the Luminous Flux of 1800LM is not relevant for plants.

there is no general conversion between Lumen and PPF as this is depending on the light spectrum.

If you know PPF you can calculate PPF / AREA minues losses due to reflection (it is also a big difference if the environment is closed or open). as the angle is 180° a lot of light is going to the side instead towards your cultivation area.

I personally would not buy a light without knowing the PPF (if its for plants ;-) )

My Comment: a grow light lighting manufacturer should provide a PPF Value not just ppfd.
This is equivalent to the LUMEN-Value. Also in the standard lighting industry LUMEN is used to calculate the efficiancy not LUX!!

The efficacy of a light is calculated using PPF / Watt (Consumption)

PPF [µmol/s]
Consumption [W]

µmol/Ws

one Ws = J (Joule)
Result µmol/J

PPFD is equivalent to LUX.

therefore a single PPFD should never be used for such a calculation.
Taking the average of multiple PPFD reading makes more sense but there is a a lot of space for mistakes and cheating.

PPF can only be measured witha integrated sphere, while PPFD is measured using a “handheld” spectrometer”
Because only lighting laboratories useually have an integrated sphere, most of the “Independent” tests are made with spectrometers°

Thanks for you question! With these specs, your best option would be to use the lumens calculator since those are the values provided. “Cool White” would be the closest match to the Kelvin temperature listed. Once you have the Moles/day conversion, you can compare this to the DLI (Moles/day) chart for VFTs to see if the lights would be enough. I hope this helps!

Plants Grow LED Light T600-LED18W
Size: 60 x 5x 5 cm
Crystalline Ball (RA>80.22-24LM): 96PCS 2835SMD
Colour Index: RA>=80
Luminous Flux: 1800LM
Luminescence Angle: 180
Degree Power: 18W
Colour Temperature: 5000-5500K

Hope you can help!

Hi Jason, I’m glad you found it helpful! Regarding DIY reflectors, Mylar can be an effective and inexpensive option for reflecting light. If you are looking to build a hood or reflector around the lights themselves, I would aim to use something that has a low risk of catching fire or melting like aluminum sheeting. I hope this helps!

I’m looking for a way to make a diy reflector for my lights – any ideas?

Hi Guillermo, it sounds like the light intensity is working great for some of your plants while for others it may be a little too intense. While red leaves on Nepenthes aren’t necessarily a bad thing, it is still possible to burn them with artificial light. The red color could have something to do with the species or genetics like you said, but if it seems like they are becoming unhealthy or if you prefer they looked more green, moving them farther from the light would be a good idea. I hope this helps!