My growing collection of neps

Ertiocx

Carnivorous Plant Addict
I had an itch to overhaul my grow area so that's what I've done.

New shelving arrived in perfect condition:
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New shelf assembled:
This one's 182.9 × 61 × 213.4 cm (W x D x H) compared to my old shelf's 121.9 x 45.7 x 182.9 cm, so I now have twice the area per shelf.
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Here's the new shelf set up:
The mylar is just held together with tape for now because I'm going to need to redo some stuff once the new lights come in.
The old shelf was about 4 trays wide.
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The new lights will be the same as my current ones, but with LM301H emitters instead of my current LM301Bs. They should be around 10% higher output. The current lights produce around 350 umol/m^2 s for the plants directly below, and around 200 umol/m^2 s for the ones off to the sides.
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H2O

Administrator
Staff member
Looking awesome! The setup is clean and organized, definitely shows off your well grown plants.
 

Ertiocx

Carnivorous Plant Addict
Here's one I haven't previously posted. I received this during the @Jake Chickenbark moving sale last year.

N. x harryana:
May 11, 2023: It had many more leaves when I first received it in Apr 2023, but those almost all burnt off under my lights.
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Oct 10, 2023: This plant has spent the last 5 months growing just 3 leaves. It has been a very long acclimation, but it looks like this latest tendril may finally pitcher.
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Fingers crossed for now. It could still abort if it doesn't like my new shelf.
 
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Ertiocx

Carnivorous Plant Addict
One of the two lights I ordered came in today. I replaced the 240W LM301B fixture that was lighting my neps with this.

3.0 umol/J, about 10% higher efficacy compared to the LM301B emitters.
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Everything looks to be in order
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Here's the new and old PPFD map for my shelf. LM301H are just a marginal improvement over LM301B, on average producing some 10-15% higher PPFD.
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x harryana is about to pitcher for the first time ever, I made some bokeh balls with a speedboosted portrait lens
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One of the two lights I ordered came in today. I replaced the 240W LM301B fixture that was lighting my neps with this.

3.0 umol/J, about 10% higher efficacy compared to the LM301B emitters.
View attachment 26119

Everything looks to be in order
View attachment 26120

Here's the new and old PPFD map for my shelf. LM301H are just a marginal improvement over LM301B, on average producing some 10-15% higher PPFD.
View attachment 26121

x harryana is about to pitcher for the first time ever, I made some bokeh balls with a speedboosted portrait lens
View attachment 26122
How much light does the kitty get? This is important:p:p
 

Ertiocx

Carnivorous Plant Addict
I picked up a cheap PAR meter (PAR-380) from aliexpress and took it to work to compare to an Apogee MQ-500.
It reads within a couple percentage points of the Apogee, unless the light contains a lot of 390 to 400 nm light.
Looking at the spectral response curves for the two sensors show that this results from the PAR-380 having a sharper cut-off at 400nm than the MQ-500:
1700719699316.png

Just for fun, I compared the PAR-380 to a lux meter (LX1330B) and the Photone android app.
For these images, numbers that appear in red are measurements with more than 10% difference compared to the Apogee MQ-500.

PAR-380:
1700792982266.png

LX1330B lux meter:
I've converted the lux values to PPFD for this image, since I know that for this light 63 lux = 1 umol/m^2 s as measured using the MQ-500.
Most of the measurements are within 10% of the MQ-500, save two where the large size of the sensor head caused me to hold it in such a way that the sensor was slightly shaded.
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Photone (Android):
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Photone works great when the light source is directly overhead. Anything more than a couple degrees out from under the light results in big errors, with some measurements off by more than 50%. This is because phones don't have cosine-correction and the Android app tells you not to use any sort of diffuser.

Funny enough I was able to make Photone accurate by calibrating it with a tissue covering the light sensor to act as a diffuser.
This doesn't actually help anybody because you still need either a lux or PAR meter to calibrate against.
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Result:
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Based on this I'd guess that the iPhone version of Photone works much better than the Android version. That said, the weight of paper used as the diffuser is going to change the PAR reading, so I still wouldn't trust the app for much more than measuring relative brightness.

I couldn't find good cosine response curve so I made one:
The dashed line in both charts shows what a perfectly corrected cosine response on an ideal sensor would look. like.
See: https://en.wikipedia.org/wiki/Lambert's_cosine_law
See: https://www.e-education.psu.edu/eme812/node/896
- The top graph shows light intensity (PPFD, 0 to 100%) as a function of zenith angle, 0 being directly overhead.
- The bottom graph shows the difference (PPFD %) between the measurement from the indicated sensor and an ideal sensor.
- The error bars here are ± standard deviation of 6 samples.

The PAR-380 has decent cosine correction, it's not as good as the Apogee sensor, but it's perfectly workable unless you need the extra accuracy and precision. My phone's light sensor has no cosine correction, and you can clearly see how the readings fall off if the light source is more than a couple degrees off from directly overhead. Using a diffuser improves this somewhat, but it's still terribly imprecise compared to a proper sensor. The error bars are huge for both sets of Photone measurements because the poor cosine correction means small changes in the direction of incoming light result in large differences in the measured PPFD.
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