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Started germinating a CSI: Humboldt - Three Queens (White fire 43 x Bubba) this morning...
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ICMag with help from Phlizon, Landrace Warden and The Vault is running a NEW contest for Christmas! You can check it here. Prizes are: full spectrum led light, seeds & forum premium access. Come join in!
3snowboards
Active member
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Guest
Thank goodness for ignore lists. Wish I could do more, but I'll take the free thread bumps. 
Both girls are doing well, ordered another small fan for the room, and an open-box Canon DSLR. Maybe get some better shots...
VG Bubba
CSI Bubba
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Both girls are doing well, ordered another small fan for the room, and an open-box Canon DSLR. Maybe get some better shots...
VG Bubba
CSI Bubba
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G
Guest
CSI Three Queens showing taproot after 25 hours germinating. Popped her in the ground this morning.
CSI Bub day 5
VG Bub day 10
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CSI Bub day 5
VG Bub day 10
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Three Queens seed is threatening to break the surface of the soil after 7 hours. I planted her about a half inch down, or so I thought. We'll see if she's really that vigorous in a few days. All the seeds in this run were procured between 2015-16 and stored in my closet. That these are all germinating so readily is a pleasant surprise for me.
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Mattbho
Active member
Has to do with leaf temp the leds dont heat the leaf like the hps running slighly warmer solves the issue . It was like a giant lightbulb went off when i gave in to the 80 deg vs 76. Info scattered everywhere ill see if i cant get u a few sources while at work tonight/this week
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Guest
Thanks for the follow-up. I spent a little time researching and found a few articles describing the ideas behind the Leaf Surface Temperature (LST) and the effects different types of lights have on them. Here's a good one showing some examples with FLIR cameras:
https://www.maximumyield.com/the-re...face-temperature-and-lighting-spectrum/2/3226
I've been averaging around 78F the past few days, but with RH levels around 65%. Higher humidity can increase the LST, but I'm not sure if the references to "plant-optimized LEDs" apply to my light or not. I've got the red spectrum in there... Guess I'll have to figure out a way to measure the LST and find a happy range. For now, I won't hesitate to let the temp drift up to 80F and see how they respond. I used to deal with saw-toothed leaves all the time with the old HPS years ago, so trying to let that go.
Thanks for turning me on to this!
EDIT: Using a cheap IR non-contact forehead thermometer, I scanned the surfaces of both Bubba S1s with an ambient temp of 77.5F:
VG's - 71F avg
CSI's - 72.5F avg
With this basic info, I can deduce that I have good efficiency with my light spectrum and/or too little humidity. I cranked the light up to it's max (635 watts) and will check things again in an hour or two. Found another article with cannabis-specific info here:
https://medteknutrients.com.au/leaf-surface-temperature-lst-in-hydroponic-growing/
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https://www.maximumyield.com/the-re...face-temperature-and-lighting-spectrum/2/3226
I've been averaging around 78F the past few days, but with RH levels around 65%. Higher humidity can increase the LST, but I'm not sure if the references to "plant-optimized LEDs" apply to my light or not. I've got the red spectrum in there... Guess I'll have to figure out a way to measure the LST and find a happy range. For now, I won't hesitate to let the temp drift up to 80F and see how they respond. I used to deal with saw-toothed leaves all the time with the old HPS years ago, so trying to let that go.
Thanks for turning me on to this!
EDIT: Using a cheap IR non-contact forehead thermometer, I scanned the surfaces of both Bubba S1s with an ambient temp of 77.5F:
VG's - 71F avg
CSI's - 72.5F avg
With this basic info, I can deduce that I have good efficiency with my light spectrum and/or too little humidity. I cranked the light up to it's max (635 watts) and will check things again in an hour or two. Found another article with cannabis-specific info here:
https://medteknutrients.com.au/leaf-surface-temperature-lst-in-hydroponic-growing/
Peace
DM
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Guest
Welp, the ambient temp jumped to 82 and holding steady for now. RH dropped down to 55%, which needs to come up a bit...but more on that later.
Leaf Surface Temps
VG Bub - 75.5F
CSI Bub - 77F
The two plants seem to have slightly different leaf structures from what I see so far, which could possibly explain the difference in leaf temps. Will continue monitoring and make adjustments as necessary. Aiming for 77-82F range at the leaf.
As for the humidity, it seems to me that an ambient temp of 81F should see the leaf temp between 78-81F, given appropriate RH levels to facilitate an ideal transpiration rate. Since my leaf temps are lower than that ideal range while my ambient temps are right where they should be, it tells me they are transpiring too quickly, AKA, relative humidity is too low. But I don't want to push it too far, too fast, so continuing to monitor and make incremental changes to find the right balance.
Here's the VG Bub from earlier today
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Leaf Surface Temps
VG Bub - 75.5F
CSI Bub - 77F
The two plants seem to have slightly different leaf structures from what I see so far, which could possibly explain the difference in leaf temps. Will continue monitoring and make adjustments as necessary. Aiming for 77-82F range at the leaf.
As for the humidity, it seems to me that an ambient temp of 81F should see the leaf temp between 78-81F, given appropriate RH levels to facilitate an ideal transpiration rate. Since my leaf temps are lower than that ideal range while my ambient temps are right where they should be, it tells me they are transpiring too quickly, AKA, relative humidity is too low. But I don't want to push it too far, too fast, so continuing to monitor and make incremental changes to find the right balance.
Here's the VG Bub from earlier today
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Guest
I managed to successfully kill the CSI Three Queens seed with water...again... 
Put another one in a paper towel this morning. Think I'll start germing the other two on Sunday the 20th.
Leaf surface temps this morning were down about 0.5F cooler than last night, even though ambient temp was up 1.5F compared to the same timeframe. I misted the surface of the bed again. Going to try and keep the RH over 70% today and see how that works. Got a small humidifier going, may need something else too...
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Put another one in a paper towel this morning. Think I'll start germing the other two on Sunday the 20th.
Leaf surface temps this morning were down about 0.5F cooler than last night, even though ambient temp was up 1.5F compared to the same timeframe. I misted the surface of the bed again. Going to try and keep the RH over 70% today and see how that works. Got a small humidifier going, may need something else too...
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Guest
CSI Bubba Day 7
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Baa sorry to hear it. They really need no water after the initial watering in.
But at least you have more seeds, sounds like a nice one.
But at least you have more seeds, sounds like a nice one.
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Guest
Yeah, no biggie. As long as 1 of the 7 comes through, I'm not sweating it. Those Bubba's seem pretty slow to me already, so I'm sure the other 'brids will catch up in no time.
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Guest
I finally hit a good leaf surface temp on both Bubba girls tonight. 77F and 77.5F for VG and CSI, respectively. That was achieved with an ambient temp of 82F and 68% RH.
So my leaf temps are about 5F cooler than my ambient temps. Great! Right? Ideally, there shouldn't be that big of a temperature difference between the two... Maybe 2-3F cooler at the leaf, sure. So that tells me the leaves are still transpiring (cooling) too much, which means RH needs to go up.
I sprayed the top of the soil 4 times today to keep the RH up... Screw that noise. My 6" hurricane fan is pulling 435 CFM out of the 250 cubic foot room. Ventilation 101 recommends displacing the room's air every 2 minutes, which means my fan is almost 4x more powerful than what it needs to be... Crap!
I have some cover crop seeds on the way, need to get those going right away. Guess I'll need to find a weaker fan, too. Anybody need a gently used 6" Hurricane? lol
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So my leaf temps are about 5F cooler than my ambient temps. Great! Right? Ideally, there shouldn't be that big of a temperature difference between the two... Maybe 2-3F cooler at the leaf, sure. So that tells me the leaves are still transpiring (cooling) too much, which means RH needs to go up.
I sprayed the top of the soil 4 times today to keep the RH up... Screw that noise. My 6" hurricane fan is pulling 435 CFM out of the 250 cubic foot room. Ventilation 101 recommends displacing the room's air every 2 minutes, which means my fan is almost 4x more powerful than what it needs to be... Crap!
I have some cover crop seeds on the way, need to get those going right away. Guess I'll need to find a weaker fan, too. Anybody need a gently used 6" Hurricane? lol
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3snowboards
Active member
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Guest
So the 2nd Three Queens seed I germinated for 24 hours and didn't see it crack open, but I put it in the dirt anyways and started germinating the 3rd seed. It cracked open this morning, so stuck her in the dirt next to the other one. It's a race!
Was happy to see my ambient temp and RH were holding steady this morning at around 83F and 67%, respectively. Leaf surface temps were both 77.5F, happy with that. Just need to work on reducing the air flow to minimize the temp difference between ambient and leaf surface...
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Was happy to see my ambient temp and RH were holding steady this morning at around 83F and 67%, respectively. Leaf surface temps were both 77.5F, happy with that. Just need to work on reducing the air flow to minimize the temp difference between ambient and leaf surface...
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Can you get a fan speed controller. I'd rather keep an overkill fan in the kit then get rid of it.
Would lowering your light to warm the leaf surface more have the same effect? Do you have a par meter
3snowboards I remember your first grow was some seeds you found growing out of a crack in the pavement, and everybody came out to help you with that. And now you wanna troll this good dude who's tryna grow weed the right way. Short memory.
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I was just looking at the fan speed controller options, great idea! Never had to slow down my fan before, old HPS habits. Got one coming tomorrow.
When I started, the light was 30" above the plants. I moved it down to 24" a few days ago to answer the same question you had...and the answer was "yes". That's how I was able to get the surface temps where I wanted. But I'd next want to fix the glaring issue with air flow so I can minimize the need to mist the soil 3-4 times a day. Then, I'll continue playing with light height, intensity, etc...
Thanks for the thoughtful responses!
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3snowboards
Active member
G
Guest
Both girls seem to be responding well to the adjustments over the past few days.
VG Bubba Day 13
CSI Bubba Day 8
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VG Bubba Day 13
CSI Bubba Day 8
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Received the fan speed controller today and hooked it up. Turned the fan down as low as it would go, which reduced the fan's wattage use by about 50%. So it should be pulling around 200CFM now, which is much better than 400+ for this room. The RH started climbing right away and has plateaued about 10% higher than before the change. I'll wait a little while longer and check the leaf surface temps and see if that is helping to close the gap between Ambient and Surface temps.
I also hooked up a new Vornado mini desk fan. It doesn't push as much air as the other 4" clip-on fan I was using, so I turned the 4" off and just using the Vornado for circulation now.
Here's a pic from the new camera, too. There's a learning curve, so bear with me...
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I also hooked up a new Vornado mini desk fan. It doesn't push as much air as the other 4" clip-on fan I was using, so I turned the 4" off and just using the Vornado for circulation now.
Here's a pic from the new camera, too. There's a learning curve, so bear with me...
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