Red vs Blue spectrum in veg

I had recently noted in a post that running R/FR spectrums in veg and early flower could cause stretching, greater internodal length and loss of density in the flowers. Maybe I misunderstood, have it backwards or it may well be genetics rather than the lamp spectrum but I think I’m seeing the opposite under HLG QB 288 RSpec boards.

I added a HLG VEG-PRO 250 a while back and was surprised to see Rspec boards rather than the BSpec they had used in previous veg lamps. Since changing to this lamp I have been seeing more plants with very tight nodes . . . these are all under 4” tall and, except for the runty little WW XXL on the left are wider tan the 4” pots:

May just be genetics but I’ve noticed it with strains from Sensi, Brother’s Grimm and Barney’s since replacing the Mars lamp I had previously used during veg. Possibly just the result of a better overall spectrum than I had with the previous veg lamp.

Thoughts and opinions, anyone else seeing this under RSpec lamps?

Honestly I’m not sure. With the new grandmaster with spectrum tuning I believe they recommend full blue spectrum or cool white during veg and they use the red and green for flower. I could be remembering it wrong but build a soil has a side by side VS a full spectrum light.

When it comes to HLG my blackbird it just white with a couple strips of red. Sometimes I get really tight internodal (spelling) spacing, other times it’s not so tight so I assume that’s just genetics. I will say it outperforms my ac infinity lights in quality and quantity.

R/FR lighting makes a plant think it’s in the shade so it puts growth into the stems to grow taller. Bruce Bugbee speaks of this in a couple of his videos.

I agree with you, that’s what I have “known” for 40+ years, reds cause stretch . . . I’m not questioning the science behind it.

But for reasons as yet unknown, it’s not what I’m seeing in my veg room. I really expected the BSpec boards when I ordered the veg lamp but HLG’s VEG-PRO has RSpec boards and I am seeing a significant increase in plants with very short internodal lengths since replacing the Mars Hydro lamp I last used.

The lamp is the only thing I’ve changed in the veg room, same media, same nutes . . . I’ve used Metal Halide, T5’s and LED’s by Mars Hydro, Barinna, Viparspectra, Vivosun and now HLG in veg. I’ve grown thousands of plants over the years and I noticed the short node spacing right away. My first thought was genetics, but since the change I’ve ran 8 different strains from 3 different breeders and I’m seeing a significant increase in plants with very tight nodes.

From all the research I have been doing lately on the far red lighting you are spot on with your assessment. From my understanding of it this can also hamper your flower development on density

I added an HLG 320 FR to the flowering room beside an original Scorpion RSpec lamp at the same time I added the VEG-PRO lamp. I’m seeing no noticeable difference in bud density between those grown under RSpec or the FR spectrums. I’ve have a Diablo 200 around somewhere that was previously used in veg . . . I’ll have to flower a plant under it and see how structure/density compares.

As to the issue of node spacing in my garden I now believe it to be a temperature issue rather than spectrum related. Since changing lamps my veg area has been running cooler overall, 70-72℉ with virtually no change in day/night temps. I had high temp alarms set but no low temp triggers, I’ve raised the day temps and will see if node spacing improves.

I really appreciate that info. I’m starting to think that the far red lighting it just a lot of hype nothing more

Node spacing relies on the spectrum, genetics, and the environment. I’ve noticed that the warmer the environment the more space there is between nodes. I’ve noticed that the spectrum and genetics play a bigger part in it than the environment does.