Specific light wavelength causing more photobleaching/light damage than others?

[xDannyS_]

I have a few different grow lights from sunlight, sansi, spider farmer, viparspectra, and just some regular 6500k T5's. I've noticed that plants photobleach and produce anthocyanin much more easily under some lights than others, despite receiving about the same PPFD. The most noticeable difference being between the viparspectra, the spider farmer, and the regular 6500k T5s. I can put plants literally 0.5cm from the light with the regular 6500ks, pretty close to the spider farmer, but not close with the viparspectra before photobleaching or excessive anthocyanin production occurs. The difference between the viparspectra and the other 2 is that it has a lot more orange (580-600nm) light, although I'm not sure how true that is because it seems the spectrums change for the same light from website to website for the viparspectra and spider farmer. I'm just wondering if anyone has any knowledge or personal experience with this?

 

[crimsonecho]

i feel i get better colors under my higher kelvin cree cxb1830 diodes. just a personal feeling not tested knowledge.

 

[Rocket Soul]

I have a few different grow lights from sunlight, sansi, spider farmer, viparspectra, and just some regular 6500k T5's. I've noticed that plants photobleach and produce anthocyanin much more easily under some lights than others, despite receiving about the same PPFD. The most noticeable difference being between the viparspectra, the spider farmer, and the regular 6500k T5s. I can put plants literally 0.5cm from the light with the regular 6500ks, pretty close to the spider farmer, but not close with the viparspectra before photobleaching or excessive anthocyanin production occurs. The difference between the viparspectra and the other 2 is that it has a lot more orange (580-600nm) light, although I'm not sure how true that is because it seems the spectrums change for the same light from website to website for the viparspectra and spider farmer. I'm just wondering if anyone has any knowledge or personal experience with this?

Anthocyanin production is very much dependent on high light intensity + too low temps. Google high irradiation reaction for more info. Hope it helps.

 

[Melquides]

Well, It is great to find people talking about something thats been ALL on my mind. We run Phlizon 3000 COBs . Three rows of plants on a 35 ft table. The center row started redding/purple a Lot, some leaves went yellow white first, then to red/purple. some straight to white/yellow. I can actually see lines in lower leaves, where upper leaves shaded the lower leaves. Now lots of the discolored fan leaves are dying, shriveling. I have some plants on the outside that have loads of their fan leaves, and are still green. Currently waiting on a PAR meter to see how the center row measures out, also moved one healthy ish green plant from the outter rows to the center to see how it reacts. Left a few green plants on the outter row to see if they stay green and the other starts discoloring and losing leaves.

 

[xDannyS_]

Well, It is great to find people talking about something thats been ALL on my mind. We run Phlizon 3000 COBs . Three rows of plants on a 35 ft table. The center row started redding/purple a Lot, some leaves went yellow white first, then to red/purple. some straight to white/yellow. I can actually see lines in lower leaves, where upper leaves shaded the lower leaves. Now lots of the discolored fan leaves are dying, shriveling. I have some plants on the outside that have loads of their fan leaves, and are still green. Currently waiting on a PAR meter to see how the center row measures out, also moved one healthy ish green plant from the outter rows to the center to see how it reacts. Left a few green plants on the outter row to see if they stay green and the other starts discoloring and losing leaves.

I've come to the conclusion that it's dependent on a lot more factors than just the strength of blue light. Adding more red light allowed my plants to take the same amount of blue light without any photobleaching or turning purple. The same applies to IR. You gotta be careful with the effects of red and IR light or you'll end up with too much. What fixed the problem the most for me was not using the reflective floor that comes with grow tents. The underside of leaves seems to be A LOT more sensitive to photobleaching than the upper sides. This was only noticeable in my tent where the floor was reflecting a lot of light upwards and directly hitting the undersides. It didn't help much in my other tent where the canopy, pots, and vegetation blocked most light from even hitting the floor.

 

[Melquides]

I swear it did feel like folks in my thread were Gaslighting me when i posted about the lights causing the bleaching and color. I tried showing multiple pics, explaining, and pretty much everyone tells me im crazy and its not my lights. I have come to the same conclusion as you, that there has to be multiple factors. The people advising in my thread can not be totally wrong, some are seasoned. But there is for sure a Correlation, which does not always equal Causation. The concencus was my EC was to high, and temps got too high (minisplit is down). EC likely locked out, temps were up, with CO2 and close lights.. I think it blew through some Immobile Elemet and started eating the fan leaves after the high EC lockout.. my best guess. The bottoms of the plants in question are still green with less crispy fans.

 

[Rocket Soul]

I swear it did feel like folks in my thread were Gaslighting me when i posted about the lights causing the bleaching and color. I tried showing multiple pics, explaining, and pretty much everyone tells me im crazy and its not my lights. I have come to the same conclusion as you, that there has to be multiple factors. The people advising in my thread can not be totally wrong, some are seasoned. But there is for sure a Correlation, which does not always equal Causation. The concencus was my EC was to high, and temps got too high (minisplit is down). EC likely locked out, temps were up, with CO2 and close lights.. I think it blew through some Immobile Elemet and started eating the fan leaves after the high EC lockout.. my best guess. The bottoms of the plants in question are still green with less crispy fans.

There seems to be a few different types of bleaching; green leaves going pale and then this youre seeing, like an accelerated fade going thru several colors.

 

[OneHitDone]

I have a few different grow lights from sunlight, sansi, spider farmer, viparspectra, and just some regular 6500k T5's. I've noticed that plants photobleach and produce anthocyanin much more easily under some lights than others, despite receiving about the same PPFD. The most noticeable difference being between the viparspectra, the spider farmer, and the regular 6500k T5s. I can put plants literally 0.5cm from the light with the regular 6500ks, pretty close to the spider farmer, but not close with the viparspectra before photobleaching or excessive anthocyanin production occurs. The difference between the viparspectra and the other 2 is that it has a lot more orange (580-600nm) light, although I'm not sure how true that is because it seems the spectrums change for the same light from website to website for the viparspectra and spider farmer. I'm just wondering if anyone has any knowledge or personal experience with this?

Still the great mystery in bro science led land.

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