NCDude
New Member
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
It looks like the 'jello cups' clones are doing well...no dome for them?
It looks like the 'jello cups' clones are doing well...no dome for them?
300W LED vs. 400W HID Demonstration
- Thread starter Keith Lake
- Start date
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Didn't know you could bury that much of the stem and be OK.
Good stuff!
thanks b
The RRs are little sponges, the biggest mistake people make is keeping them too wet, roots need oxygen. I put mine about 4-6" into the dirt [or whatever] for two reasons: the media tends to suck the plugs dry, not allowing for stem rot, and adventitious rooting will occur along the portion of the stem that is buried, stabalizing the plant. I have had plants lodge [fall down, go boom!] from planting the plugs at soil level.
b
Didn't know you could bury that much of the stem and be OK.
Good stuff!
thanks b
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Two were doing OK, one was going downhill, and none had any root growth at all, so I switched them over to RR's.
I'm going to put some kind of a dome over the VK-cross clones tonight.
I'll get some pics up.
thanks NCDude
Two were doing OK, one was going downhill, and none had any root growth at all, so I switched them over to RR's.
I'm going to put some kind of a dome over the VK-cross clones tonight.
I'll get some pics up.
thanks NCDude
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
I'm going to try that at the next opportunity!
One of the reasons I like to put a layer of Hydroton on top of the media is because of the additional roots that develop under there, but I like the benefits of your more radical approach.
Shortens the plant and gains more roots. What's not to like?
Just out of curiosity, did a mentor pass down that technique, or did you come up with it?
take care b
I'm going to try that at the next opportunity!
One of the reasons I like to put a layer of Hydroton on top of the media is because of the additional roots that develop under there, but I like the benefits of your more radical approach.
Shortens the plant and gains more roots. What's not to like?
Just out of curiosity, did a mentor pass down that technique, or did you come up with it?
take care b
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Mom and clone update.
The mom's growth exploded two days after top-dressing with an additional two Tbsp of OC+.
Almost seems like she doubled her size in less than a week. PPP is a beautiful strain. No discernible aroma yet.
She responded to LST really well, but this strain at this age is on the delicate side and needs to be handled carefully.
On to the clones.
I tried to fit all the clones and the mom in the cab, and it just wasn't working, so I set up a little nursery area in the garage with an 18w 6500k CFL, a tray and dome, and a seedling heat mat.
Now the mom has a lot more room, and the clones are in a better environment too. Should I keep them at 18/6, or have them at 24/0?
I just read somewhere that flowering clones have to be at 24/0 to revert back to veg. Is that true?
I have them all at 24/0 for now.
OK, here I got tired of compromise and decided to do things right.
The clones have their own nursery and light schedule.
The mom's gonna be happier too.
I noticed one set of alternating nodes on one branch, so she's starting to mature, but it's still early yet.
thanks peeps
Mom and clone update.
The mom's growth exploded two days after top-dressing with an additional two Tbsp of OC+.
Almost seems like she doubled her size in less than a week. PPP is a beautiful strain. No discernible aroma yet.
She responded to LST really well, but this strain at this age is on the delicate side and needs to be handled carefully.
On to the clones.
I tried to fit all the clones and the mom in the cab, and it just wasn't working, so I set up a little nursery area in the garage with an 18w 6500k CFL, a tray and dome, and a seedling heat mat.
Now the mom has a lot more room, and the clones are in a better environment too. Should I keep them at 18/6, or have them at 24/0?
I just read somewhere that flowering clones have to be at 24/0 to revert back to veg. Is that true?
I have them all at 24/0 for now.
OK, here I got tired of compromise and decided to do things right.
The clones have their own nursery and light schedule.
The mom's gonna be happier too.
I noticed one set of alternating nodes on one branch, so she's starting to mature, but it's still early yet.
thanks peeps
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Amazing how adaptable plants are!
I'm not so crazy about embracing change.
Just came home from lunch and snapped a few pics of the clonatorium.
Not going to count my chickens before they hatch, but I'm feeling pretty good about this. There is good humidity under the dome, the foil pan is transmitting the warmth from the heat mat very well, and the RR's seem to be working so far.
I've got 8 PPP clones and the 2 VK-cross flowering clones. None of them look worse than they did yesterday, so yeah, I'm optimistic.
The RR's are turned upside down, so they stand up well, and I made the smallest hole possible in them for the cuttings so that the stems are in good contact with the RR all the way around.
I'm keeping 1/8" of tap water in the bottom of the pan to keep the RR's moist.
Any suggestions, comments, criticisms, slaps upside the head, etc., would be very welcomed as I'm a complete noob at this.
Hope you're all having a green day!
Amazing how adaptable plants are!
I'm not so crazy about embracing change
.Just came home from lunch and snapped a few pics of the clonatorium.
Not going to count my chickens before they hatch, but I'm feeling pretty good about this. There is good humidity under the dome, the foil pan is transmitting the warmth from the heat mat very well, and the RR's seem to be working so far.
I've got 8 PPP clones and the 2 VK-cross flowering clones. None of them look worse than they did yesterday, so yeah, I'm optimistic.
The RR's are turned upside down, so they stand up well, and I made the smallest hole possible in them for the cuttings so that the stems are in good contact with the RR all the way around.
I'm keeping 1/8" of tap water in the bottom of the pan to keep the RR's moist.
Any suggestions, comments, criticisms, slaps upside the head, etc., would be very welcomed as I'm a complete noob at this.
Hope you're all having a green day!
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Cool, thanks guys!
I'll just keep running them at 24/0 then.
I've been taking the dome off for a minute or so 2-3 times a day.
They're still looking OK.
This is worse than waiting for seeds to sprout, lol.
Cool, thanks guys!
I'll just keep running them at 24/0 then.
I've been taking the dome off for a minute or so 2-3 times a day.
They're still looking OK.
This is worse than waiting for seeds to sprout, lol.
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Only thing I can say was already said. Keep your eye on the moisture content of the plugs. Rooters.
Does the pan ever evaporate ss? I would say let it get dry for a little while every 24 hrs or so .
They look great though. Positive actions result in positive results!
Peace ss. You don't need luck. You got this maaaaan!
Brotha bro GO!
Only thing I can say was already said. Keep your eye on the moisture content of the plugs. Rooters.
Does the pan ever evaporate ss? I would say let it get dry for a little while every 24 hrs or so .
They look great though. Positive actions result in positive results!
Peace ss. You don't need luck. You got this maaaaan!
Brotha bro GO!
The Lurker
New Member
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
^^^^^^
Yep, there's a finer line between keeping clones saturated vs. drowning them, or drying 'em out. I've also seen some good results from folks using pure coco coir for cloning, just stick 'em in and keep 'em moist, not even using a humidity dome. Coco seems like an ideal material for holding moisture without getting too wet. Want to try that next time I'm runnin'...
Do you have a Thermostat for your heating mat, SS? What temps are you running at the pan bottom? Easy for those mats to get too warm if you're not careful.
...B's been growin' since '67, eh? Guess he's one of the few folks around here who can say 'dude' - and mean it. I've got this picture of him now in my head looking like Jeff Bridges from The Big Lebowski... 
I know you're supposed to be a fairly 'neutral party' during these tests - sometimes it's gotta be hard to remain that way. About wanting to spill the beans, I understand...
Interesting observation, I think their overall concept could use a general redesign. Their New 330W Model is a bit perplexing, too. They've gone from Red, White, Blue ---> White, Red, Deep Red, have crammed 62 LEDs (2x) in the same (15"x20") board(!), minus a couple inches on the long end to hold the drivers, and bolted a couple of short finned heat sinks to the top. Here's a quote from their site:
I want to have heavy units! Tells me they're probably putting adequate heat sinks in 'em. Anything too light makes me suspect. I don't care if they're 'automotive rated' or not, having a 'Caution:Hot Surface' sticker on the fins doesn't make me feel good about their TM.
That (new) board and those (passive) heat sinks might work if you've got 1W LEDs in them; any more and I want a big ol' heat sink with lots of fin surface - and fans.
----------
Seems like their lens spread causes more problems than it solves if you have to keep the unit so close that the individual colors don't blend well. Smaller watts with tighter angles and spacing would probably work better.
It'd be a good idea if we can get a pic of all these models showing coverage on white posterboard at ~3-6", as you mentioned...I think it'd be much less of an issue in the standard models once you get past ~4-5" or so, at least with 90-120 deg - and uniform spacing of colors.
---
Hey, whatever happened to the HSS? Did they make you give the unit back, or were you allowed to keep it for veg stuff/'rainy day' use?
-TL
^^^^^^
Yep, there's a finer line between keeping clones saturated vs. drowning them, or drying 'em out. I've also seen some good results from folks using pure coco coir for cloning, just stick 'em in and keep 'em moist, not even using a humidity dome. Coco seems like an ideal material for holding moisture without getting too wet. Want to try that next time I'm runnin'...
Do you have a Thermostat for your heating mat, SS? What temps are you running at the pan bottom? Easy for those mats to get too warm if you're not careful.
...B's been growin' since '67, eh? Guess he's one of the few folks around here who can say 'dude' - and mean it.
I've got this picture of him now in my head looking like Jeff Bridges from The Big Lebowski... I know you're supposed to be a fairly 'neutral party' during these tests - sometimes it's gotta be hard to remain that way. About wanting to spill the beans, I understand...
Interesting observation, I think their overall concept could use a general redesign. Their New 330W Model is a bit perplexing, too. They've gone from Red, White, Blue ---> White, Red, Deep Red, have crammed 62 LEDs (2x) in the same (15"x20") board(!), minus a couple inches on the long end to hold the drivers, and bolted a couple of short finned heat sinks to the top. Here's a quote from their site:
HSS said:
I want to have heavy units! Tells me they're probably putting adequate heat sinks in 'em. Anything too light makes me suspect. I don't care if they're 'automotive rated' or not, having a 'Caution:Hot Surface' sticker on the fins doesn't make me feel good about their TM.
That (new) board and those (passive) heat sinks might work if you've got 1W LEDs in them; any more and I want a big ol' heat sink with lots of fin surface - and fans.
----------
Seems like their lens spread causes more problems than it solves if you have to keep the unit so close that the individual colors don't blend well. Smaller watts with tighter angles and spacing would probably work better.
It'd be a good idea if we can get a pic of all these models showing coverage on white posterboard at ~3-6", as you mentioned...I think it'd be much less of an issue in the standard models once you get past ~4-5" or so, at least with 90-120 deg - and uniform spacing of colors.
---
Hey, whatever happened to the HSS? Did they make you give the unit back, or were you allowed to keep it for veg stuff/'rainy day' use?
-TL
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Fake it till ya make it
It's a late 70's Centurion Lemans. The geometry of the 70's Japanese sport tourers and road bikes fits me very well. I enjoy restoring those nice old frames as much as riding them. Probably more, judging by my belly.
Yikes! Totally missed that one. I was happy thinking about all the good rooting hormones and bennies in the RR's too. Thank you bro!
Thanks again! I had them way too wet. I left the dome off all day yesterday to let the RRs dry out some, and things are looking better today.
I tend to pamper my plants, so very good heads-up on that.
So, I guess I shouldn't keep any water at all at the bottom of the tray, just re-moisten the plugs?
I'll get an RH meter and thermometer in there tonight. I bought some small RH meters to use for curing that should work.
Thanks!
Kudos on your description of the mod to your tray. I could follow along and visualize it. It's hard as hell to describe stuff like that so people can can understand what you're thinking.
Using them upside down just made more sense to me. I don't like the big hole they come with, neither for sprouting seeds or the cuts. For seeds, I just tear a piece off the plug and fill it after I plant the seed, but for the cuts, I wanted really good contact with the media, and since I wanted them to stand up without a plastic tray, I just flipped them. I used a little bamboo skewer to make a much smaller hole to insert the cuts into.
The benefit of the heat transfer to the larger base of the plug through the foil pan, and the more logical use of the shape was purely accidental, but I think it may work really well for rooting. Plastic trays just don't make the same kind of contact or transmit heat well, and the much smaller tapered end of the plug would make very poor contact with the tray even if I could keep it vertical with that end down.
Looking very good for a 1st approximation
Fake it till ya make it
It's a late 70's Centurion Lemans. The geometry of the 70's Japanese sport tourers and road bikes fits me very well. I enjoy restoring those nice old frames as much as riding them. Probably more, judging by my belly
.Yikes! Totally missed that one. I was happy thinking about all the good rooting hormones and bennies in the RR's too. Thank you bro!
Thanks again! I had them way too wet. I left the dome off all day yesterday to let the RRs dry out some, and things are looking better today.
I tend to pamper my plants, so very good heads-up on that.
So, I guess I shouldn't keep any water at all at the bottom of the tray, just re-moisten the plugs?
I'll get an RH meter and thermometer in there tonight. I bought some small RH meters to use for curing that should work.
Thanks!
Kudos on your description of the mod to your tray. I could follow along and visualize it. It's hard as hell to describe stuff like that so people can can understand what you're thinking
.Using them upside down just made more sense to me. I don't like the big hole they come with, neither for sprouting seeds or the cuts. For seeds, I just tear a piece off the plug and fill it after I plant the seed, but for the cuts, I wanted really good contact with the media, and since I wanted them to stand up without a plastic tray, I just flipped them. I used a little bamboo skewer to make a much smaller hole to insert the cuts into.
The benefit of the heat transfer to the larger base of the plug through the foil pan, and the more logical use of the shape was purely accidental, but I think it may work really well for rooting. Plastic trays just don't make the same kind of contact or transmit heat well, and the much smaller tapered end of the plug would make very poor contact with the tray even if I could keep it vertical with that end down.
with the VKs
and had a very very green day!
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
thanks Go!
I had them way too wet.
I'm glad my ego didn't get in the way of asking for help and guidance.
Pretty sure the cuts wouldn't have made it if I had done things my way.
I love this place!
thanks Go!
I had them way too wet.
I'm glad my ego didn't get in the way of asking for help and guidance.
Pretty sure the cuts wouldn't have made it if I had done things my way.
I love this place!
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
there is coco in my future also
I do have a thermostat for the mat, but not currently using it. The mats I use keep temps 10F above ambient, so tray temps have been around 80-85F. I'll get a thermometer and RH meter in there tonight.
I'm still in the process of figuring out my role in these grows. Being too neutral or too opinionated are both best avoided, and emotionalism also.
Consumer Reports, the publication, reports a lot on automobiles. Their reports are factual, sterile, and completely devoid of the kind of enthusiasm that automobile enthusiasts have.
Consequently, the only thing I use CR for as far as rating automobiles goes is their frequency of repair charts. The car reviews are useless to me because they don't love cars. They just report on them. That's fine for the masses.
I think a good consumer reporter should balance facts and more esoteric stuff, but learning where the boundaries are is hard, and I'm still very much learning.
I recall that we talked about attaching some heat sinks to the top of the HSS panel in that journal. I wonder if that had anything to do with the design of their new light?
I will do that when I do the intensity/temp measurements on the grid. It's on my list, and I will do my best to include all that data in this journal. Life is busier than usual right now, but will do asap.
I still have it, but planning to sell it. I didn't mention this in that comparison grow, because it's something that probably only bothers me, since I've asked other owners and none have complained, but the pitch of the electronic buzz it makes drives me nuts.
I'm extremely finicky about noise, so I didn't comment on it because it's something others seem to tolerate without problems, but it's enough to keep me from using the light because I have other options.
I've protected my hearing quite well throughout my life. At my last audiogram, the technician came up to me afterwards and asked me if I might be related to bats, lol.
nope, just full of guano
there is coco in my future also
I do have a thermostat for the mat, but not currently using it. The mats I use keep temps 10F above ambient, so tray temps have been around 80-85F. I'll get a thermometer and RH meter in there tonight.
I know you're supposed to be a fairly 'neutral party' during these tests - sometimes it's gotta be hard to remain that way. About wanting to spill the beans, I understand...
I'm still in the process of figuring out my role in these grows. Being too neutral or too opinionated are both best avoided, and emotionalism also.
Consumer Reports, the publication, reports a lot on automobiles. Their reports are factual, sterile, and completely devoid of the kind of enthusiasm that automobile enthusiasts have.
Consequently, the only thing I use CR for as far as rating automobiles goes is their frequency of repair charts. The car reviews are useless to me because they don't love cars. They just report on them. That's fine for the masses.
I think a good consumer reporter should balance facts and more esoteric stuff, but learning where the boundaries are is hard, and I'm still very much learning.
I recall that we talked about attaching some heat sinks to the top of the HSS panel in that journal. I wonder if that had anything to do with the design of their new light?
---
I will do that when I do the intensity/temp measurements on the grid. It's on my list, and I will do my best to include all that data in this journal. Life is busier than usual right now, but will do asap.
I still have it, but planning to sell it. I didn't mention this in that comparison grow, because it's something that probably only bothers me, since I've asked other owners and none have complained, but the pitch of the electronic buzz it makes drives me nuts.
I'm extremely finicky about noise, so I didn't comment on it because it's something others seem to tolerate without problems, but it's enough to keep me from using the light because I have other options.
I've protected my hearing quite well throughout my life. At my last audiogram, the technician came up to me afterwards and asked me if I might be related to bats, lol.
nope, just full of guano
Lemon Paradise
New Member
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Reading this journal is like going to school... in a good way.. Lurker always has some real deep thoughts,, lol
oh, and
great laugh on a Friday morning.
Reading this journal is like going to school...
in a good way.. Lurker always has some real deep thoughts,, loloh, and
great laugh on a Friday morning.
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
check & check
The reading above is the temp of the bottom of the pan.
I know I'm a gadget freak, but you gotta get one of these.
check & check
The reading above is the temp of the bottom of the pan.
I know I'm a gadget freak, but you gotta get one of these
.Propa Gator
New Member
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Ooh, ooh. I do want one of those.
Shoot the leaves, Mr Gadjet. Both sides
Ooh, ooh. I do want one of those.
Shoot the leaves, Mr Gadjet. Both sides
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
Will do Mr. Gator.
Very useful tool in the garden.
Here's something on using one to evaluate plant stress, which would be very handy as regards finding the sweet spot with indoor lighting.
"Infrared thermometers are useful tools for measuring temperature of plants, tools equipment and anywhere where you want to discover fast and accurate surface temperatures of objects.
Another great reason for using an infrared thermometer is to measure leaf temperatures. A study by the Department of Land Resource Science at the University of Guelph in canada concluded that an infrared thermometer more accurate than thermocouples for leaf temperature measurements. Errors are estimated to be less than 0.2 °C when measuring leaf temperatures in a typical leaf chamber
It has been discovered that the differential between ambient air temperature and leaf temperature (ΔT) is a great indicator of a crops stress, especially from lack of irrigaion water and the subsequent yields.
A recent study by P. Mannini and S. Anconelli found that on irrigation controlled fruit, using the differential between ambient air temperature and leaf temperatuere (ΔT) was a better indicator of water stress and subsequent yields than other commonly used techniques as the tensiometer, evaporimeter and soil moisture.
*
They found that the best yields occured on irrigated strawberries when the ΔT was less than 1°C
*
They found the worst yields occured on a non-irrigated strawberries when the ΔT was more than 4°C.
The USDA has also researched and discovered a correlation between plants stress levels and a rise in leaf temperature rise above ambient air temperature. The IR gun provides a simple, fast and accurate means of testing the differential temperature (ΔT).
Conditions for testing (ΔT).
*
Plant leaf surface must be dry.
*
Use only when wind is blowing at less than 10 mph.
*
Keep the sunlight at your back.
*
Use a reliable thermometer for determining the ambient air temperature.
*
Take I.R. readings from foliage only during the peak sunlit hours of the day, when stress is most likely to occur. Therefore, take readings from 11 AM to 4 PM during the summer and from 1 PM to 3 PM during the winter.
*
If air temperature is much cooler than normal, then I.R. plant stress will not be measurable with this instrument.
*
Remember that when you shine at an angle, the beam being cast will be oval, (similar to a flashlight beam) just something to bare in mind.
*
You must have at least 2 minutes of sunlight immediately following an interruption by clouds.
*
Remember that when you shine at an angle, the beam being cast will be oval, (similar to a flashlight beam) just something to bare in mind.
*
Hold the sensor so that the beam will not see the sky or dirt, we are trying to eliminate these as confounding variables.
*
As a good practice, take multiple leaf readings and average the results readings. The more samples you take the more reliable the results.
Finally record the differential temperature between ambient air and average foliage temperature. The magnitude of this temperature difference is a measure of the stress level of the plants.
Distance : Spot Ratio
The infrared thermometers have a ratio such as 12:1 which is the distance to spot ratio. This means that the beam diameter cast on the leaf will be 1/12th of the distance from the sensor to the object. For example if you stood at 12 inches away from the leaf, the beam of light cast on the leaf would measure 1 inch in diameter, in other words the closer you are to the leaf the more concentrated the area will be that you measure. The higher the distance:spot ratio, the better quality the thermometer and you can also take accurate measurements from further away from the target.
In general, a differential temperature of +1or 2 degrees Celsius is very good. If the foliage is 10 °C warmer than ambient air, the plant is seriously stressed and cause of problem needs to be determined. Generally speaking the cooler the crops stay over the course of the growing season, the higher the yield and the better the quality of the crop."
It would appear that some of the difficulties in obtaining accurate readings outdoors would not be an issue indoors, so they're even handier in that environment.
This is a very useful gadget.
Will do Mr. Gator.
Very useful tool in the garden.
Here's something on using one to evaluate plant stress, which would be very handy as regards finding the sweet spot with indoor lighting.
"Infrared thermometers are useful tools for measuring temperature of plants, tools equipment and anywhere where you want to discover fast and accurate surface temperatures of objects.
Another great reason for using an infrared thermometer is to measure leaf temperatures. A study by the Department of Land Resource Science at the University of Guelph in canada concluded that an infrared thermometer more accurate than thermocouples for leaf temperature measurements. Errors are estimated to be less than 0.2 °C when measuring leaf temperatures in a typical leaf chamber
It has been discovered that the differential between ambient air temperature and leaf temperature (ΔT) is a great indicator of a crops stress, especially from lack of irrigaion water and the subsequent yields.
A recent study by P. Mannini and S. Anconelli found that on irrigation controlled fruit, using the differential between ambient air temperature and leaf temperatuere (ΔT) was a better indicator of water stress and subsequent yields than other commonly used techniques as the tensiometer, evaporimeter and soil moisture.
*
They found that the best yields occured on irrigated strawberries when the ΔT was less than 1°C
*
They found the worst yields occured on a non-irrigated strawberries when the ΔT was more than 4°C.
The USDA has also researched and discovered a correlation between plants stress levels and a rise in leaf temperature rise above ambient air temperature. The IR gun provides a simple, fast and accurate means of testing the differential temperature (ΔT).
Conditions for testing (ΔT).
*
Plant leaf surface must be dry.
*
Use only when wind is blowing at less than 10 mph.
*
Keep the sunlight at your back.
*
Use a reliable thermometer for determining the ambient air temperature.
*
Take I.R. readings from foliage only during the peak sunlit hours of the day, when stress is most likely to occur. Therefore, take readings from 11 AM to 4 PM during the summer and from 1 PM to 3 PM during the winter.
*
If air temperature is much cooler than normal, then I.R. plant stress will not be measurable with this instrument.
*
Remember that when you shine at an angle, the beam being cast will be oval, (similar to a flashlight beam) just something to bare in mind.
*
You must have at least 2 minutes of sunlight immediately following an interruption by clouds.
*
Remember that when you shine at an angle, the beam being cast will be oval, (similar to a flashlight beam) just something to bare in mind.
*
Hold the sensor so that the beam will not see the sky or dirt, we are trying to eliminate these as confounding variables.
*
As a good practice, take multiple leaf readings and average the results readings. The more samples you take the more reliable the results.
Finally record the differential temperature between ambient air and average foliage temperature. The magnitude of this temperature difference is a measure of the stress level of the plants.
Distance : Spot Ratio
The infrared thermometers have a ratio such as 12:1 which is the distance to spot ratio. This means that the beam diameter cast on the leaf will be 1/12th of the distance from the sensor to the object. For example if you stood at 12 inches away from the leaf, the beam of light cast on the leaf would measure 1 inch in diameter, in other words the closer you are to the leaf the more concentrated the area will be that you measure. The higher the distance:spot ratio, the better quality the thermometer and you can also take accurate measurements from further away from the target.
In general, a differential temperature of +1or 2 degrees Celsius is very good. If the foliage is 10 °C warmer than ambient air, the plant is seriously stressed and cause of problem needs to be determined. Generally speaking the cooler the crops stay over the course of the growing season, the higher the yield and the better the quality of the crop."
It would appear that some of the difficulties in obtaining accurate readings outdoors would not be an issue indoors, so they're even handier in that environment.
This is a very useful gadget.
Re: 420 Consumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID
That is pretty interesting SS.
I wouldn't have thought leaf to air temperature would be such a big deal. It does make sense in terms of how much the plant evaporates and is indeed a place to gather infrared heat!
You should check the hid vs led leaf temps...it would be interesting to see the heat from each unit and how much it is effecting the leaf temp.
Good stuff SS!
-Go
That is pretty interesting SS.
I wouldn't have thought leaf to air temperature would be such a big deal. It does make sense in terms of how much the plant evaporates and is indeed a place to gather infrared heat!
You should check the hid vs led leaf temps...it would be interesting to see the heat from each unit and how much it is effecting the leaf temp.
Good stuff SS!
-Go
