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Test of different reflective materials for DIY grow space

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Interesting results - everything one reads on the internet claim Grow room Mylar to be more reflective than Aluminum foils, so this multi-point test showing Al foil and emergency Mylar to be more reflective is quite something. I wonder if there are more people who have done this test and come to the same conclusion?
 

Max - LEDTonic

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Interesting results - everything one reads on the internet claim Grow room Mylar to be more reflective than Aluminum foils, so this multi-point test showing Al foil and emergency Mylar to be more reflective is quite something. I wonder if there are more people who have done this test and come to the same conclusion?
Thanks for the feedback! We thought it was interesting, too. Logic says that diamond mylar which is designed for this context should outperform most of the other materials. But, as mentioned in the video, we used a generic and unbranded diamond mylar from our local hydroponics store. Other brands and versions may perform better, or, at least I hope they do.

There are some other tests online but we haven't seen any with this level of detail. A single spot measurement is rarely enough information, which is what most tests are based upon.
 

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I enjoyed that, thanks!

iirc from another similar test a while back that emergency blankets or foil had caused hot spots on a plant, supposedly from the creases. May it just be that those materials are a little too efficient if VPD and DLI weren't taken into consideration? idk
 

Max - LEDTonic

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I enjoyed that, thanks!

iirc from another similar test a while back that emergency blankets or foil had caused hot spots on a plant, supposedly from the creases. May it just be that those materials are a little too efficient if VPD and DLI weren't taken into consideration? idk

Hotspots from homemade reflective materials shouldn't be a problem as long as one is keeping the materials reasonably flat. We've experimented a fair bit with reflective materials and have never been able to see an extreme hot spot created anywhere. As seen in the video above, the light intensity is differing slightly across the board as the sides aren't reflecting light evenly.

We once managed to create a hotspot with a home-made reflector. It was a stainless steel bowl with a polished inside. The hot spot was around twice as bright (1000 PPFD) as the area just outside the hotspot (500 PPFD). My point is that if a small hot spot is twice as bright as the average light intensity, it should be very visible.
hotspot.png


How intense would a hot spot need to be for a plant to burn? 1200 PPFD? 1500 PPFD? 2000 PPFD?
Let's use 1500 PPFD as an example.

If one is growing with 500 PPFD average, the hotspot would then need to be 3x as intense as the average light intensity. If one is growing with 1000 PPFD, it would need to be 1.5x the average intensity.
If you have any pointers on how I best could achieve a hotspot with either aluminum foil or blankets, I'd be happy to try and create one. If we can find a hot spot that is 1.5-3x stronger than the average light intensity, we may be onto something :)
 

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Hi guys!

We just made a short video where we test the reflectivity of different materials commonly used in DIY grow spaces.
Enjoy!
Excellent test, thanks very much for sharing. As you say, surprising results. I thought that painted white walls would do a bit better, and I would not have predicted the very large effect of walls vs. no walls. It bears keeping in mind though that the roll of wall reflectivity would vary a lot with different sizes of grow space - the larger the space, the lower the role of wall reflectivity.

Thanks again for putting the test together and sharing the results.:pighug:
 
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