[v1ru5]

Hey,

About to drop roughly 3k EUR on four Model 4VL's.
This price includes taxes and shipping and all that.

The COBs I will get will be the 1750k variety.

Why dat low kelvin you say? I have noticed with HPS's that the redder the spectrum, the higher the yield.
Fuck those balanced spectrum bulbs and all, I want the reddest of the red in HPS, and I bet the same goes for LEDs.

I have not seen much pictures of Timber Grow Lights grows, a lot of posts with only text, only a picture here and there, but that does not deter me from buying.
I have had great success with both COB LEDs and normal LEDs, and I bet these new COBs are the bomb.

I wonder if anyone out there is running these 1750k Veros...

Any comments?

[h.h.]

I have a couple of the 1750's in my mix.
Can't make any definite statements one way or the other.

From Google:
There is a higher percentage of deep red in the shade. It signals the plant to seek light resulting in stretch. The bluer wavelengths result in greater bulk.

In my mind, using stoner logic, alternating the percentages will result in stretch, bulk, stretch, bulk, stretch or in other words, growth. IDK. I'm experimenting without any controls.
Those using deep red are using cheap low powered bulbs for a half hour morning and night for the Emerson effect.
I think the attraction to HPS comes from the intensity rather than the wavelengths.
I think, for flower, 3,000k would be more productive as your main light.

[Koondense]

If you ask me I'd stick with 3000K or eventually mix the 1750K with 3500K cobs, as hh pointed you can expect more stretch with only 1750K.

Cheers

[v1ru5]

Stretch will not be a problem.

As with HPS's with redder spectrums yield more, I don't think this matter is any different in LEDs.

I mean, using a metal halide for veg, HPS for flower, HPS for veg, metal halide for flower, metal halide for both veg and flower, and using HPS for both veg and flower, the last option produces the most yield.

So that is why I want to go full 1750k.

Any thoughts?

PS. And I have used different HPS bulbs, metal halides, LEDs, CFLs and sulphur plasmas in my grow career spanning 15+ years... Just to clear this out so you don't think I am basing these claims on some hearsay; Only cold hard experience here. :P

[h.h.]

https://gpnmag.com/article/effects-o...ght-on-plants/

Looking at the picture, the plants with a small percentage of blue light have a better root system on a smaller plant with no loss of foliage.

I believe the 1750k LED's have less of a full spectrum than a HPS light is. They're more of a rose color than a yellow color. They're red because the other wavelengths are filtered out. Stronger filter and they're less intense and less efficient. The deep red wavelength is not absorbed by the leaf as well. It shines through the leaf.

With that I don't know. Haven't tried it.
Some of the best information I found on the RIU forum, but nothing to the far extreme like you suggest.

[h.h.]

https://www.rollitup.org/t/testing-ti...935965/page-14

[Hermen_eutics]

My rig has a 1750K cob at about 75W. I also run 2x v29 gen7 version 4k and one gen7 v29 3k along with 4 cxb 3590 3500k. All day it's about 580w. This is my first run with this iteration so just interested in observations. I've chatted with the riu guys, and got the idea from 'PSU' over there. The overall rig is above 50% efficient even with the 1750

Ive got a 730nm lights out bar that i accidentally left on over night 1x at the beginning of flowering. This single event might have cause the luxury stretch on one of the plants OR it may be the 1750 cob. Not sure. Also the intense flowering response might be more dramatic because of the 1750. Again not sure. Ive run both Kali Mist and Sin Mint Cookies a couple times before so I hope to have a couple useful observations about the effect of this cob as the flowering continues. So far the only difference i notice is that it seems to dissipate more heat. I expect that in time the effect would become easier to see.

I got a bunch of pics but struggling with the upload and a newer camera

[Hermen_eutics]

After two weeks of 12/12 i believe that the 1750 initiates more stretch in this plant than when grown under the 4k-3k mix. I also think that there seems to be more bud initiation on both plants.
However the Kali Mist under the same fixture is showing minimal stretch at day 14.

The sin Mint Cookies has grown to ~36" and it's ~8" from the cobs. I've got about 6" more of height to give up. I didnt raise the lamp hoping that the intensity would limit stretch.

The reading on the lux meter is nuts and that level of irradiance is not sustainable. I plan to increase the gap when stretch is done.

[-BRR-]

By running the 1750k exclusively you would be doing us all a great service I think. How will we ever know otherwise?

The great kelvin exploration.

[Hermen_eutics]

Originally Posted by -BRR-

By running the 1750k exclusively you would be doing us all a great service I think. How will we ever know otherwise?

The great kelvin exploration.

Im not sure of all the negs that would accompany a 1750k only rig. Loss of efficiency would he a huge one. Spectrum wise it couldn't be that great either. have you looked at Dawg and PSU over on RIU? They have posted about their adventures with 1750.

Ive only gone 15 days with 2 plants under this rig but for sure Ive not seen this many bud sites in previous grows. The cob isnt the only variable so the observation is very general.

As far a kelvin temps in general this rig has ~200W of 3500, ~180W of 4k, ~85W of 1750k, ~90W of 3k. It's not great for vegging. This is first flowering run using updated cobs and adjusted K temps. I think it looks very promising especially if I can maintain good nutrition.

With all those diff temps I try to hang the fixture as high as possible to blend the spectrum. This plant stretched so much that it's not happening. I'm trying to compensate by rotating the pots under the lamp.