PAR meter for LED recommendations

[cypo74]

Hi lads, just wondering if anyone has and recommendations for a PAR meter to use with my 640w LED 

After having some issues with light stress, which was solved just by moving the light higher, it’s annoyed me enough to set off my OCD and I now want to get the lighting spot on. 
just made me wonder just how far from optimal I am regularly 

 

anyway, cheers for any ideas lads 

[SmokeTester]

Proper PAR meters are expensive. You probably want an Apogee, they start around £500 

An alternative is an app for your phone that will give you an approximation.

 

 

[cypo74]

Cheers mate

[Gaijin]

Let me try and find a link I saved. Someone here buys a cheaper light meter (it's, like £20) but knows how to adjust its reading to make it correct. There's a video. I'll be back with an edit  

 

Here's the post  It was @MindSoup He's full of useful bits like this 

 

 

Edited March 6, 2022 by Gaijin

[cypo74]

Awesome, cheers mate

[Guest]

Really isn't necessary.  The plants are the best indicator money can buy.  What setting do you have it on, in what space and at what canopy height?  Chances are it's something else thats off and the high ppf is just aggrevating it. 

[cypo74]

It’s a 1.2m2 tent, 640w skysabre light

8 gallon fabric pots

humidity 55

Air temp 26-27

root temp 23-24

light height was about 30” now raised to full height, can’t measure right now as it’s the dark period, but probably about 40”

light was at full power

 

i lowered it about 6” the other day and almost immediately I started getting some minor yellow tipping on the leaves, so back up to full height

ive just started week 7 of flower on Saturday, organic guanokalong nutes

 

this LED malarkey I’d quite different to HPS hahaha

Edited March 6, 2022 by cypo74

[MindSoup]

@Gaijin 

 

As fatboy says most of the time its not all that necessary, but if you're low on headroom it comes in handy. 

[cypo74]

Cheers for the link mate

[Guest]

That's really pushing the envelop in terms of ppf if you're just getting to grips with led.  You'd need your VPD to be bang on and feeding a nice high npk.

550w in that space would be easier for you to get used to, before you push it hard. 

[cypo74]

Just bought a temp gun and started messing with VPD using the dimlux VPD charts 

[catweazle1]

3 hours ago, MindSoup said:

@Gaijin 

 

As fatboy says most of the time its not all that necessary, but if you're low on headroom it comes in handy. 

Just got the UNI-T luxmeter as per your Migro link. 15 quid. Shall try it with my scopex 350 shortly.

Edited March 6, 2022 by catweazle1

[cypo74]

14 hours ago, MindSoup said:

@Gaijin 

 

As fatboy says most of the time its not all that necessary, but if you're low on headroom it comes in handy. 

I downloaded the Photone app reviewed in the video and added the diffuser and I’m getting a result of 250 at canopy level……. That can’t be right as I do get nice yields

 

even holding it directly under the light it’s only 330

Edited March 7, 2022 by cypo74

[inceywinceyspider]

@cypo74 I've used that app without a diffuser and found it was fairly close to what I'd expect from the manufacturer par map, I didn't think of using a diffuser it would be better, but would expect it to cut out the light by maybe half or more so you'd need to adjust for that.

[MindSoup]

@cypo74 are you also paying attention to wether its x10 or x100? Took me a minute to figure that one out