San Diego Finest Cuts #3

[Tardigrade]

also, your quote is hilarious...The closer you are to the lights, the more the leaves look awful, but it seems happy enough

I've enjoyed success using them at a distance but up close, simply too bright...same results, it fries leaves

 

[ECtraveler]

I got events both weekends and unfortunately won't be able to make either but I'll be there in spirit.

Btw GT - I had a few people ask about you at Chalice.

 

[Terpene]

What is the height of the grow space you have the MxE in?

Is that the true color on the PS or is that due to you lights?

Its an 3.5'W x 5.5'L x 8'T walk in closet with the lights raised up against the ceiling (they're on chains if I want to run smaller plants).

You got me, I was being lazy. The Purple Slurms are under the 240w Blackstar (which refuses to die so I can replace it with screw ins), so thats what the plants look like pink lights on. I don't mind the pink LEDs, but it makes it more difficult to spot nutrient deficiencies / pests / etc.

Terp, that Honduras x Alien OrangeADE is beast! Those fan leaves look like they will be a foot wide soon.

also, your quote is hilarious...The closer you are to the lights, the more the leaves look awful, but it seems happy enough

I've enjoyed success using them at a distance but up close, simply too bright...same results, it fries leaves

Heh, the main fans are about 10 inches across right now and we've still got 6 weeks till flowering is even remotely a possibility. Everyone that walks into the yard has about the same response: "Whoa, that thing is a tree!"

Screw ins seem to cook the leaves up close no matter what I do. Doomsday and I had a conversation about how LEDs don't emit enough UV to turn my transitions lenses dark - so thats indication enough that the leaves aren't getting burned by UV. Maybe IR or just actual light brightness / photon density? All I know is that the buds seem perfectly happy up to 2 inches from the bulbs, but the leaves are hideous if you get inside about 6-8 inches.

 

[DoomsDay]

The conversation terp mentioned above is the exact reason I'm doing a bit of tinkering with these LED cobbs.... long run these lights are still the best bang for the buck, now if only we can get them to stop burning leaves while plants are relatively close while buds remain happy is the problem.... I'll post up more on this project by this evening hopefully.

 

[ECtraveler]

Terp- Do your transitions turn with UVA, UVB or both?

 

[ECtraveler]

From Fluence's website on about their "UVSpec" spectrum of LEDs.

With a peak wavelength of 400nm, UVSpec™ is designed to provide beneficial photomorphogenic responses by creating a mild stress response in plants. As an example, when applied correctly, research shows increased THC content in cannabis plants. When applied incorrectly, research shows UV stress causes photoinhibition of chloroplasts, resulting in lower biomass production, photobleaching and death of leaves.

https://fluence.science/technology/physiospec-broad-spectrum-led-lights/

 

[ECtraveler]

IMO LED "caps" on for veg if you're within 18" of the lights, caps off in flower.

 

[DoomsDay]

Outstanding thought process through the led lighting issues. The one thing we've all seemed to note is that too close can happen with these bulbs and actually happens faster than hps bulbs. Only time I remember similar results from high pressure lights was when I did vertical barebulbs.... a sheet of glass may just be the solution as its a minimal filter between the bulbs themselves and the plants material

 

[Terpene]

Terp- Do your transitions turn with UVA, UVB or both?

According to the internets, Transitions rely on UVA to darken. I can hold them up to the bulbs and they stay clear, so the LEDs are emitting very little UVA light.

IMO LED "caps" on for veg if you're within 18" of the lights, caps off in flower.

Now before you go saying this, let me remind you, I do all of my vegging under 14w bulbs without covers and the plants are fine - right up until the point they get really close to the capless bulbs (within a couple inches). In flower, buds up top are big, healthy and perfectly normal if you ignore the ugly leaves. I haven't seen any reduction in size due to being close to the lights - just crispyness in the leaves.

I think the rule here is: if you care about the top leaves looking pretty and perfectly green, you may want to reconsider shoving them right up against the bulbs. Otherwise, meh.

There's also another (probably most likely) bit we should consider - I am not dialed. All of my plants are from seed / new lines I've never worked with before. These leaves dying could be a result of a magnesium or other deficiency, or just the fact that a 7 foot tall equitorial landrace sativa really doesn't like being rootbound in a 3.5 gallon container.

 

[ECtraveler]

A
Now before you go saying this, let me remind you, I do all of my vegging under 14w bulbs without covers and the plants are fine - right up until the point they get really close to the capless bulbs (within a couple inches).

I have my veg split into several different zones. One area with 315w CMHs, one with T-5s and another that I have half split with bare LEDs and the other half with the covers still on. The only area I've been experiencing problems have been under the bare LEDs and when I move sick plants out from underneath them they recover. I say with absolute certainly that I believe the bare LEDs are not promoting optimum growth when set too close to the plants.

 

[ECtraveler]

According to the internets, Transitions rely on UVA to darken. I can hold them up to the bulbs and they stay clear, so the LEDs are emitting very little UVA light.

That makes sense if they only react to UVA but not UVB or UVC.

All types of UV radiation are known to damage various plant processes.

Such damage can be classified into two categories: damage
to DNA (which can cause heritable mutations) and damage to physiological processes.

 

[ECtraveler]

I'll post pictures tonight for comparison of the same strain of seed starts under the 3 different types of lighting

 

[Terpene]

I say with absolute certainly that I believe the bare LEDs are not promoting optimum growth when set too close to the plants.

I usually flower at least 6 inches away from the larger bulbs (14/16w) as the leaves tend to burn when you get closer. I always find myself inching the plants closer and closer, but 8 inches off the plants seems to be the sweet spot. I know Blynx is running his lower wattage bulbs (8-10w) more or less right on top of the canopy. What distance are yours from the plants?

 

[ECtraveler]

Fuck a fire! Here's to hoping there's still a Med Tree left tomorrow.

 

[unregistered190]

Fuck a fire! Here's to hoping there's still a Med Tree left tomorrow.

This, good vibes to all in the path of the fires

 

[ECtraveler]

...and safe. That was a quick but very close call.

 

[onavelzy]

...and safe. That was a quick but very close call.

Good to hear you're safe and in the clear EC. I was reading in another thread a couple of long time ICMAG folks got hit by the fires up north, including getting injured trying to fight the fire.

 

[DoomsDay]

NuHoly shit that was a scary ass moment last night. Fire directly over my ridge about 1 mile north of me. Here's to the firefighters that put in work last night!


And in other news the light prototype has been completed.... Now to see how she works.

 

[Grow Tech]

Are those LEDs retrofitted in to a hps hood? They dont look like the normal scew ins

 

[DoomsDay]

They are indeed retrofitted into a standard air cooled good so I can remove the heat from the room and get an ac going in there again.

The idea sprouted out of the bulbs still putting off quite a bit of heat when you end up burning 20+ in a small area. Since the plan is to run roughly 60 of these bulbs in flower, it came time to.open them up, remove the bulb, heat sink, and driver and made some modifications. As it's hung now, the bulbs actually face up, away from the plants and directly at the reflector material in the hood, this proved to be Drastically dimmer than the bulbs just kept screw in style. Once I get home this evening I'll be flipping them to face them the opposite way within the hood and see what the result is.

Stay tuned....