I'm stumped!

[gbauto]

Interesting thread.
ken, you are working with approximately 5 sq ft of canopy.
The fixtures you're using state they consume about 88 watts with all leds running.
That's 176 watts of blurple leds.
I agree with the responses, you need more light.
A ball park estimate for your spoace to achieve adequate light intensity would be 50 watts/sq ft of canopy using old-tech diodes or HID.
That's250 watts for that space using blurples.
A fixture using more efficient diodes would equal that with 100 fewer watts.

[kenKgrow]

Hi gbauto.
I did asked HLG about that. They said that their 135 watt fixture would be too much for this space and recommended that I go with the 95 watt Rspec, which is what I did. I guess if it's not enough I can add a second one.

[YYCannabis]

Blurple lights are the worst. They truly are unreliable for calculating exactly how many watts of useable light is actually reaching the plant. The “UV diodes” suck a lot of power, but only deliver useable light at a very short distance. Every grower that uses blurple lights is truly wasting tons of electricity for minimal (if any) gain.

[kenKgrow]

gbauto, Thanks for those numbers. When I run them using my actual canopy of 3.75 sq ft times 50 watts of old-tech diodes = 187 watts with blurples. If I then take away 75 watts (just a guess) for using more efficient diodes I'm left with 112w. So the 95 watt HLG light may be undersized for this space. I should know soon.

I think the 135 watt HLG would be better for the canopy size, but the reason HLG steered me away from it was because I have so little height (about 50")

[kenKgrow]

Grouchy, I just saw your comments from 2/8. Somehow I missed it when you posted. The chart is only for my auto grows. You are correct, over time, as yields have dropped, flowering and harvest times have accelerated. By "harvest time" I mean the age of the plant when I harvest. And no, I do not harvest early. The plants begin flowering earlier and finishing up earlier. Just when it looks like it's time to sit back and enjoy the stretch and watch the buds fatten up, they're done. By "done" I mean few viable leaves and the stigmas are mostly brown.

With the new HLG light, the plants look much healthier, but still tiny. Right now I have a plant growing that is supposed to reach over 100cm. It has 8 sets of leaves, it's flowering and is only 4" tall. It's 18" from the light. I tried having the light closer on a previous plant, but it burned it. Based on recent experience, I expect it wont even be a foot tall when it's done.

The one major factor that I haven't changed is humidity. I'm fixing that soon. bboyfromwayback suggested it eary in this thread. In the summer humidity is not a problem, but in the winter it get's too low. I bought a hygrometer recently and found that the humidity inside the tent is 27%. I should have that corrected by the end of the week (these problems have persisted in the summer , so it may not be the humidity level). The picture is at 16 days. It began flowering on day 18. When I first started with autos, they would be about a foot tall when they started flowering. Usually around day 21. I started another plant yesterday, so it should have the full benefit of correct humidity throughout it's life.