Back to business with the lights this morning - everything's looking good! I'm going to double-check my far red coverage this evening. If I can keep coverage good while lowering the light I'm gonna do that - I want to maintain around 900-1000ppfd but ideally I want to keep the wattage at <350... We'll see what I can manage.
I moved the light down 6" and maintained decent red coverage. I dimmed the 288s and 18s after they shut off so I can readjust and target that 900-1000ppfd range again and see where the watts land.
Oh yes - looks like I got it in just the right spot... Same wattage as my last grow under 3 * QB288v1 boards. Hopefully this grow will have a higher yield, but we'll see -- winter was tough on these plants for vegging and I'm not using screens so there are some factors against me...
A little more tinkering at mid-day - moved the light back up a couple inches and got to a ppfd of 925. Daily Light Integral at 925 on a 13.5hr window is about 45 which strikes me as a good target.
So, they will be getting a full 12 hours under full power, then 45 minutes before and after for the Emerson effect?
Not quite - you may be mixing up / combining two different effects that my fixture can accomplish. Quick picture before I explain: >>288s are 3000k (Horticulture lighting group) >>18s are Emerson boards (Horticulture lighting group) - they have a mix of 6 red, 8 deep red, and 4 far red diodes. >>FRs are Far Red pucks (RapidLED) Schedule Currently the 288s and 18s both run together from 7:00am to 8:20pm. The far red pucks turn on at 8:15pm and off at 8:30pm (running 10 minutes after the others shut off) Dark from 8:30pm to 7:00am Emerson Effect The Emerson Effect is achieved through adding the mix of red and far red. The addition of those spectra encourage the plants to photosynthesize at a higher rate. More photosynthesis during bloom should mean bigger buds. Far Red Initiation The far red pucks trigger sleep initiation. In a normal indoor grow, when the lights shut off, the plants typically take 1-2 hours to realize they need to go into sleep mode (kinda like the sun setting outdoors). By giving them far red at lights out, they go to sleep immediately - so those extra 1-2 hours can be tacked onto the light cycle. More hours of light should hopefully ALSO mean bigger buds!
That all makes sense perfect sense, thanks! I haven’t done much reading on giving plants more than 12 hours of light during flower. Is this a common practice? Can’t wait to see if you’re able to turn over some extra weight. I love your rig! It’s fun just to look at haha
I don't know how common it is. It requires extra considerations (the far red) that aren't really necessary to grow great bud. That harvest of Crimea Blue was using a regular 12:12 cycle - I only started experimenting this grow haha It's been a good grow rig for sure. I will probably finally be getting a larger tent this summer though.
Is this only for cannabis plants or all photo plants?? Vegging outside the flower tent Vegging outside the flower tent
As I understand it, many plants use phytochrome for flower response. Found this very informative. Photoperiodism - Wikipedia Sent from my XT1093 using Tapatalk
Great information. So you are running 4.5 diodes per sq ft (@ ratio 8/6/4, 620-630, 660-670,730-740nm) for Emerson effect and 1 far red diode per sq ft for initiation.
Each of the 18s has 18 diodes so 36 total over 8sq ft - 4.5 per sq ft there. The FR pucks have 4 diodes each, but they are all in a central cluster on the puck - so 1FR diode per sq ft (but not optimally spaced), yes. I've done a little testing and at the edges I'm getting a little less than 1ppfd of far red when sleep initiation is on. Clearly that's working as they are blooming just fine at the 13.5:10.5 schedule. I do think for a future fixture, however, that I would consider buying some of the individual RapidLED far red diodes and spacing them out better. I think 4 FR diodes could provide sufficient coverage for a 3x3 if they were spaced well.
That’s crazy! I know you’re experimenting right now, but in your opinion, 1ppfd of far red is adequate for wake/sleep? That was the far corner, but I can’t imagine it’s too much stronger in the middle.
It's about 11 or so directly under the diodes (I did a ppfd map a few pages back somewhere). Seems like so long as they're getting a little bit it does its magic.