High Light Intensity

I lent my par meter out a couple of months ago and only got it back this afternoon lol.
I've been flying blind for a while.
I tested the 4 x 4 tent. The plants are in flower. 12 on 12 off.
No CO2 added

Centre reading

Edge


Canopy temps ~


I'm gonna leave the light were it is for a while to see if it's too much.
Anyone else running their lights with this much intensity?

I get to 1k ASAP with my grows and haven't run anything above 1050 or so.

I've read research that states that cannabis can be run as high as 1800 but this is the first I've seen of it.

What light, dimmer setting, and hang height?

Also, do these readings and light settings make sense when compared to your settings and readings before you loaned out your Apogee?

No problem at all with that ppfd, your canopy temp is 15c or I'm missing something here ?
RIU is getting stranger by the minute...
Its like a competition here who can grow at the lowest temps possible
But seriously, if you keep RH and Temp in check you shouldn't have problems.

I normally run at around 800 - 1000 ppfd.
I'm unsure of the wattage of light, - HLG 550R - it's dimmed a bit, maybe around 350 watts.
Maybe ~ 12" - 300mm from the canopy.
15°C?, sure that's a spring day here. I've grown in cooler temperatures than that.
RH is probably ~ 90.

Damn that's way off...
A recipe for mold and bud rot
That's the problem with leds, they don't heat as much.
I would recommend making temps more to the 25-30 range, and lower rh a bit.
That rh number you have now is for 31-33c canopy...
I also think your gauge is off, 1800 ppfd from a 350w led ? Dimmed ? Sounds a bit out there but I'm not ruling it out

Moflow said:

I normally run at around 800 - 1000 ppfd.
I'm unsure of the wattage of light, - HLG 550R - it's dimmed a bit, maybe around 350 watts.
Maybe ~ 12" - 300mm from the canopy.
15°C?, sure that's a spring day here. I've grown in cooler temperatures than that.
RH is probably ~ 90.

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Check the spec sheet and it generates 1272µmol at 100% power. As soon as you move away from the light source, that values starts to drop. If you're at 350 watts that's 7/11'ths power or 63% and 63% of 1272 ≈ 8hundred and change PPFD.

15° and 90% -that's a VPD of 0.

Very good information from @DanKiller & @Delps8.
There are optimum conditions for growing but cannabis can tolerate a wide range of temperature and RH.

I've been growing like this for years in my garage. I do know what I'm doing. I'm the growing in the cold expert lol
I've a hut I use too but temperature in there is much higher ~ 24°C. ~ 1000 PPFD. RH ~ 70

I know its not directly related but here is my experice with growing under high light intensity.

I used to keep my 1k hps only 14-16 inches above my canopy. I didn't have a light meter to test the levels, but I'm sure they were pretty high. I only had light burn/bleaching twice in about 10 years of using that setup. Those plants had gotten extra tall and were almost touching the glass around the outer edge of my xxl hood.

Is anyone else running high ppfd?
DLI is around 77.

I'm still gonna leave it for a week and see what happens.

Moflow said:

Very good information from @DanKiller & @Delps8.
There are optimum conditions for growing but cannabis can tolerate a wide range of temperature and RH.

I've been growing like this for years in my garage. I do know what I'm doing. I'm the growing in the cold expert lol
I've a hut I use too but temperature in there is much higher ~ 24°C. ~ 1000 PPFD. RH ~ 70

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Sure it can, but why ?
No doubt weed is a weed and will grow under a lot of conditions, but what are you trying to achieve with growing in that temp ?
You lose in my estimate at least 50% of yield potential like that.
Better to be hps and grow like a champ haha but to each their own.

Thundercat said:

I know its not directly related but here is my experice with growing under high light intensity.

I used to keep my 1k hps only 14-16 inches above my canopy. I didn't have a light meter to test the levels, but I'm sure they were pretty high. I only had light burn/bleaching twice in about 10 years of using that setup. Those plants had gotten extra tall and were almost touching the glass around the outer edge of my xxl hood.

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Probably those two times your canopy got a lil hot, light bleaching is a myth, and you proved it again, thank you

Moflow said:

Is anyone else running high ppfd?
DLI is around 77.

I'm still gonna leave it for a week and see what happens.

Click to expand...

I think it's a waste of time, you need to couple a good temp in order for the added light to have any advantages, you can't have one without the other, but I do feel your smoke will be excellent, trichomes loves the cold.

Delps8 said:

Check the spec sheet and it generates 1272µmol at 100% power. As soon as you move away from the light source, that values starts to drop. If you're at 350 watts that's 7/11'ths power or 63% and 63% of 1272 ≈ 8hundred and change PPFD.

15° and 90% -that's a VPD of 0.

View attachment 5378495

Click to expand...

That's what I thought, the meter is definitely off.
1800 ppfd even for 550w led sounds too much.
So apparently you are at 700-800 range, which is normal and rather low.

Ok y'all

I took some more measurements about an hour ago.
The HLG is running at 361 watts on the kilowatt meter. I was close at 350 watts
The distance from the plant canopy to the light is 10" ~ 250mmm I said 12"
Apogee Par Meter reads 1800 in the middle .


Maybe @Delps8 you could recalculate your figures above now we have the exact numbers? Thanks buddy
Just in case the apogee is off.
I've tested my other grow areas and it appears to be giving the correct readings.