Good PAR meter for reasonable price?

[Loc Dog]

$160. Sounds painful. I hope you are feeling better soon

The other PAR meters were $450.

 

[Switcher56]

This discussion takes place every now and again and they always go full circle. The good thing about 'em, it refreshes the site

IMHO it is and always has been a decent investment (relatively speaking), considering the overall savings one can enjoy, not to mention in "most" cases better quality than what is available legally. It then becomes a moot point.

It was also discussed and proven that PAR meters are not necessarily out of reach ($). Now if I had a commercial grow, then I would be seeking experts advice (Shane) what is out there for the best bang for your buck. e.g you don't necessarily needs to drive your Rolls to the corner store for a qt of milk.

I will be starting my next grow last week of Aug. After rereading this thread I am going to try something different this time around. I will flower @650 for a couple of reasons, gained from experience. I was getting some light bleaching, nothing serious just the tips and a few leaf edges about 2mm and, not all girls were affected, besides genetics (where everyone falls to) it could also be their diet and perhaps to some extent, tent management.

When I said for a couple of reasons, one is the way grow (manifold technique), where I do not need the penetration of conventional LST growing, as I don't do SCROG. So I played with my light last run. I come to find out by increasing the height of the light, I had a better "overall" coverage (broader) and although not of the same intensity (umol (center of tent)), the change of height did not diminish the lights intensity significantly. IOW, the change was non linear, in favour of a slight increase in intensity, although the center of the tent decreased. That is where broader comes into play. As the light is focused in a narrow beam, increasing the height, one would expect an increase on the periphery, which it did. This discovery (by accident) could not have been accomplished without a PAR meter, regardless of price.

 

[f-e]

I think you meant to close with 'light meter' Switcher56.
Our light doesn't 'wear out' just traveling through the air, as some believe. Maybe on a quantum level, but not in our real world uses. It just spreads. The best example is the laser pointer. The dot gets bigger, into the distance. No light has been lost, it's just spreading out. Our only losses come from interactions with other materials. Roughly 10% is lost every time light goes through glass or reflects off a decent surface. When we raise the lights, more now arrives at the plants by reflecting off the walls. It's not a big change though. If 20% more light has to bounce first, so that 20% looses 10%, we are looking at a 2% light loss. It's barely measurable. We often see large greenhouses full of lights, and people wonder why they are fixed so high up. In the middle of the greenhouse, height makes no difference. If you raise the roof, you thin out the light from the lamp above you, but now lamps further away cast light upon you. It's only at the edges it matters. In the image, about 25 lights cast down, and the soup below them is consistent at any height in the middle. You just see exposure from different lamps as you move about. Many people are using a formula for light spread that's only concerned with a single lamp. Believing they must get less light as they raise the lamp. As the math is for one light source with no reflection. It doesn't transfer to the warehouse example unless as I have, you do each lamp separately and then sum up the results at various co-ordinates. It's not useful maths when we have multiple light sources. You just want that light meter of some sort.


Bleaching might also be a confusing term. We are not usually talking about a loss of colour. Usually it's a failure to produce the colour. Under HID it looked like we were burning them (and often did) but the real issue, as we push the envelope, is a failure to supply the air or food. I suspect Mg in your case Switcher. Its related to tip whitening and margins. A bit like burn, but the wrong colour. One LED supplier says Mg will be needed with their lights. It's also my biggest issue. I just can't get enough in. Mg seems eager to burn, while a lack causes early maturity. I'm having to lower Ca to levels that coco isn't happy with, just to get the Mg in there. I have fallen back on foliar application as a crutch.

 

[Switcher56]

I think you meant to close with 'light meter' Switcher56.
Our light doesn't 'wear out' just traveling through the air, as some believe.

I don't

Maybe on a quantum level, but not in our real world uses. It just spreads. The best example is the laser pointer. The dot gets bigger, into the distance. No light has been lost, it's just spreading out. Our only losses come from interactions with other materials.

Agree

Roughly 10% is lost every time light goes through glass or reflects off a decent surface. When we raise the lights, more now arrives at the plants by reflecting off the walls. It's not a big change though. If 20% more light has to bounce first, so that 20% looses 10%, we are looking at a 2% light loss. It's barely measurable. We often see large greenhouses full of lights, and people wonder why they are fixed so high up. In the middle of the greenhouse, height makes no difference. If you raise the roof, you thin out the light from the lamp above you, but now lamps further away cast light upon you. It's only at the edges it matters.

Exactly

In the image, about 25 lights cast down, and the soup below them is consistent at any height in the middle. You just see exposure from different lamps as you move about. Many people are using a formula for light spread that's only concerned with a single lamp. Believing they must get less light as they raise the lamp. As the math is for one light source with no reflection. It doesn't transfer to the warehouse example unless as I have, you do each lamp separately and then sum up the results at various co-ordinates. It's not useful maths when we have multiple light sources. You just want that light meter of some sort.

Complicated analogy and conclusion? If you are saying no need to do complicated calculations where a simple tool would provide “visual” references of what is going on. Correct? Then I agree

Bleaching might also be a confusing term. We are not usually talking about a loss of colour. Usually it's a failure to produce the colour. Under HID it looked like we were burning them (and often did) but the real issue, as we push the envelope, is a failure to supply the air or food.

... as mentioned

I suspect Mg in your case Switcher. Its related to tip whitening and margins. A bit like burn, but the wrong colour. One LED supplier says Mg will be needed with their lights.

I have seen that as well...

It's also my biggest issue. I just can't get enough in. Mg seems eager to burn, while a lack causes early maturity. I'm having to lower Ca to levels that coco isn't happy with, just to get the Mg in there. I have fallen back on foliar application as a crutch.

So what are you trying to say here? re: wrong colour (1[SUP]st[/SUP] quote).

I further understand that certain strains require a different diet, as mentioned in several areas wrt tips and tricks for successfully growing x, y or z. e.g white widow, where...

Feeding:
Keep the plant growing strong in the vegetative phase with a healthy supply of N.
As the plant begins to flower, flush the soils and prepare the plant for nutrition formulas with higher phosphorous levels.

I understand the N thing here and did as stated. I don't recommend it. Mind you that was before I changed my nutes. I regrew Ww utilizing my new nute line and she never missed a beat.

I grew Ww (2 plants) on my 3[SUP]rd[/SUP] run (old nutes) 35 and 46g respectively. I grew her again (single plant this time) on the new nutes and got 79g (just short of 3oz), I can live with that considering that Ww is a moderate yielder. I never flushed her (as previously recommended) and she never missed a beat.

Now when it comes to nute deficiency well that's a mystery. I don't go to the infirmary because I found the advice provided at times confusing (Carter has liver pills) and do my own research off site, where the information requires to be corroborated, before it is actioned upon. When neophytes post in the infirmary it is often due to lack of “general knowledge” and we further exacerbate their dilemma by providing a plethora of solutions. e.g most often “we” can't even form consensus of what his problem is.

How many times have you seen this statement... I just poped my beans, now what? Good luck! You should have carried out your research (how to grow cannabis) prior to popping said beans IMHO.


light bleach

Mag def (Sensi seeds)

I am a moderately successful (1.2g/w) neophyte because I did my homework and don't try to chase “rainbows”. I need to understand what is going on with my grow, or what has happened (after action report). I extrapolate that data and will change 1 maybe 2 things (at best) during the following run, and take lessons learned from there.

Because I grow various strains together last run (Ww, Pk and ACDC(2)) paying attention to the grow is of paramount importance IMHO. e.g one ACDC showed tip burn while the other was fine and the Pk as well. No issues with Ww. Am I going to radically change what I am doing on that single data point? No! It requires corroboration. That being said, I try to grow sats/hyb & ind separately. Because of the way I grow, this is not an issue. This is not the 1[SUP]st[/SUP] time light bleaching as occurred (all girls watered and fed the same)

I'm running a 600w in a 3x3x6ft tent (recommended) I believe a 900w would have been better suited in my situation. I tried 2x600 on a specially designed rack (side by side) and got a great spread. The heat generated was too great, even with the addition (change out) from a 4” fan to a six incher. I had to provide AC to keep temps within reason for healthy growing. The tent is/would better suited with a 900w. Something we are seeing more and more lately (coverage veging and blooming) on mfrs sites. About time! That is also when I started to notice tip burn, that time it affected all girls, because I was trying to push the “envelope”. I was growing @ 800-900 umols late flower, but... early bleaching was evident during mid to late flower. No biggy I have a spare light which will come in handy down the road, to isolate my male for seed creation.

In closing, that is why I will run at 650 and see what happens. Why? That is the simplest solution, if you believe feeding is not really a factor. The lesser of 2 evils.

In my humblest of opinions, one needs to understand what they are doing in order to remedy deficiencies etc... What ever methods are used in the analyses, the individual must understand why he may choose to do x, y or z and, appropriate measuring devices are part of “that” troubleshooting. Winging it, is not. A doctor without a stethoscope, can't diagnose shit, and why I only change 1-2 things at a time and evaluate the results of said change(s). If it ain't phoqued, don't phoque with it

 

[f-e]

Looking at the pic titled 'light bleaching' I see Mg. Not the classic stripes or spotting. It's the tips going white, and serrations rolling. That can be moisture related, but here you have the low P signs of leaves not spreading fully, and others going yellow. With that middle blade kinking to the side. Perhaps they were too dry, but I suspect Mg. I have seen this a few times and expect to see it again. As I'm unsure why the Mg is unavailable.

Our infirmary is one of the best. Site reviews often say the very best. It would be nice if everyone agreed but a spread of answers is more realistic. One thing about being a pro in that area, is knowing you don't know. Plants give clues, and there are stereotypical ones. Overall it's hard work though, with many able to mimic others, it the conditions are right.

My suspicion it's Mg has moved from an idea, to photo's. I feel confident that you should foliar them. I'm not 100% sure it will work, I'm 100% sure it's worth trying. It costs nothing.

 

[Switcher56]

Looking at the pic titled 'light bleaching' I see Mg. Not the classic stripes or spotting. It's the tips going white, and serrations rolling. That can be moisture related, but here you have the low P signs of leaves not spreading fully, and others going yellow. With that middle blade kinking to the side. Perhaps they were too dry, but I suspect Mg. I have seen this a few times and expect to see it again. As I'm unsure why the Mg is unavailable.

Our infirmary is one of the best. Site reviews often say the very best. It would be nice if everyone agreed but a spread of answers is more realistic. One thing about being a pro in that area, is knowing you don't know. Plants give clues, and there are stereotypical ones. Overall it's hard work though, with many able to mimic others, it the conditions are right.

My suspicion it's Mg has moved from an idea, to photo's. I feel confident that you should foliar them. I'm not 100% sure it will work, I'm 100% sure it's worth trying. It costs nothing.

Perhaps YOU can provide examples of what you consider light bleach and a Mag deficiency, so I have a visual because your explanation simply doesn't compute good buddy. I was talking about the center leaf, not the top left hand corner.

Wrt the infirmary, lets' just the jury is out on that matter.

Wrt bleaching, I will be able to reevaluate my position after next run. The light is much simpler (at this point) than figuring out what is wrong nute wise. I may have another idea but I don't want to go there at this point, as from what I have read my bleach is what I would deem extremely mild, almost negligible from what I have seen and read.

 

[f-e]

All we have is the inability to produce green, or green being taken away. No bleaching. UV does that when we move unaccustomed plants outside.

Here are some Mg pics from the infirmary

In your pic, blades 2 and 4 are still pointing inwards. It's a P issue, and may be linked to it's friend Mg. Blade 3 in the middle, has a kink at the end, Mg.

In the pics I have shown, you see the heat like stress on the serrations. You see colour turning to white, which would of started at the tip and then serrations like K does. Then the yellowing of the upper leaves through relocation. Most books would call these lower leaves, only differentiating between lower leaves of growing tips. These to me are upper leaves, local to the growing tip.

Mg can pull out leaving patterns like a mosaic virus. Showing all the tiny capillaries. The traditional stripes and spots don't need to be present.




If I extend my ideas into fantasy, you might have too much calcium. I suspect we add more for LEDs and it's certainly needed for loading up at transition. Soon after, with the lights going brighter, I think it's abundance isn't needed. The plants use of it drops, and with full light we may be still supplementing it pointlessly. Using up a lot of our K Mg Ca grouping. So we can't get the Mg in there. It's what I'm trialing at the moment, but my numbers are wrong. My base floranova has a label over 100% wrong, by their own admission. So I literally don't know what I was doing, to be able to share my findings. Needless to say, I won't be replacing it.

 

[Switcher56]

All we have is the inability to produce green, or green being taken away. No bleaching. UV does that when we move unaccustomed plants outside.

Here are some Mg pics from the infirmary
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In your pic, blades 2 and 4 are still pointing inwards. It's a P issue, and may be linked to it's friend Mg. Blade 3 in the middle, has a kink at the end, Mg.

In the pics I have shown, you see the heat like stress on the serrations. You see colour turning to white, which would of started at the tip and then serrations like K does. Then the yellowing of the upper leaves through relocation. Most books would call these lower leaves, only differentiating between lower leaves of growing tips. These to me are upper leaves, local to the growing tip.

Mg can pull out leaving patterns like a mosaic virus. Showing all the tiny capillaries. The traditional stripes and spots don't need to be present.

If I extend my ideas into fantasy, you might have too much calcium. I suspect we add more for LEDs and it's certainly needed for loading up at transition. Soon after, with the lights going brighter, I think it's abundance isn't needed. The plants use of it drops, and with full light we may be still supplementing it pointlessly. Using up a lot of our K Mg Ca grouping. So we can't get the Mg in there. It's what I'm trialing at the moment, but my numbers are wrong. My base floranova has a label over 100% wrong, by their own admission. So I literally don't know what I was doing, to be able to share my findings. Needless to say, I won't be replacing it.

I have never seen leaves like you have shown in my tent. (Not since switching nutes)

I found another pic that shows exactly what is going on.

and a close up of the bud at bottom left corner below


This is what I am talking about. This is what my girls look like but those buds seem to be week 3-4 of bloom, my problem seems to appear much later. Link: https://www.growweedeasy.com/cannabi...ems/light-burn
The pic is from: canopy-of-medical-marijuana-buds-flowering
Both these pics as well as the original one we are discussing here all come from the same site.

I judiciously maintain my environment between 68-78 deg F IAW the following chart when it comes to VPD

Here is a chart of the nutes I use Remo.

Numbers at the top are NPK. Where Magnifical is what they use for Cal/Mag and can be used as a foliar spray, which I'm not to keen on doing during bloom. I grow in HP Promix.
Transition week varies on how long/well I did creating my manifold. I have gone as low as 5 weeks and as long (as per normal) 6-8 weeks. I always veged 6-8 weeks when not manifolding.

Please clarify bolded text. You might be on to something (P). I might have been running my PH on the low side 6.2-6.5 IAW this chart


vice this one (that I also had)

As previously stated I only change/test 1 thing/variable per grow cycle, so I know which affected which etc... This run I want to try raising my light and aiming for 650 center of canopy vice 800-900, as it is my referenced understanding that CO2 was only required above 1000. Why? Because outside of what I have described with regards to light burn (or so I thought) seems to occur only at higher PAR values. 650 was mentioned in one of your posts.

This chart seems to say otherwise.

In closing I have not had any nute issues whatsoever since switching to Remo from GO, where I had a shit load of issues (using GO) even at lower PAR values 600-650 @ week 5-6 of flowering where I have seen P & K deficiency not mild but full blown WTF. So I simply don't know.