Ideal DLI for autos

[Son of Hobbes]

And how much wattage do you have to have to do that?

700 PPFD at 18 hours hits 45 DLI.

 

[CannabisMingus]

And how much wattage do you have to have to do that? I saw a chart that indcated that you may not need as much as your think. Chart said my 135W HLG clone would average almost 600 ppfd in a 2 x 2 tent. 700+ in the center at 18 inches and maybe 400 at the edges. That appears to be "enough, but some folks say no.

I run a Mars FC3000 in my inside tent (24x30") and it draws about 290W at the wall. I use a par meter to measure ppfd. I wouldn't rely on just on manufacturer's published specs. I have had more consistent results in dialing in light regimes by taking my own measurements. If you don't have a par meter, there is an app that some use with good results.

Did that answer your question?

 

[jdm61]

I run a Mars FC3000 in my inside tent (24x30") and it draws about 290W at the wall. I use a par meter to measure ppfd. I wouldn't rely on just on manufacturer's published specs. I have had more consistent results in dialing in light regimes by taking my own measurements. If you don't have a par meter, there is an app that some use with good results.

Did that answer your question?

No, because that would mean that I would have to buy a light meter. Dont have the spare cash for such things. Do you have to turn that light down a lot? I have a 130W Niemi (top bin diode 288 Rspec QB) and I can see signs of burn at 15 inches in a space about the same size as yours. 290w is a light that I would think would go in a space twice that size. I am wondering if I should have 150w or 180W in a 2 x 2.5 to 2.5 x 5 space.

 

[jdm61]

700 PPFD at 18 hours hits 45 DLI.

Okay. So how do you calcultate? Do you base it on the max PPFD in the center of the tent or do you average? I am try9ing to calualte for a 2x2 to 2.5 x 2.5 tent for 4 plants in SOG maybe. Center of the plants would be at the 1 foot mark and chart says like 500 at that point in a 32 x 2 tent. Close to 700 in the center of the tent. So since half of the plant is getting more and half is getting less, would 500 be a good number to use? Calculator says 500 for 18 is like 32 DLI so within spec according to the table you have?

 

[CannabisMingus]

I can see signs of burn at 15 inches

I am not saying you are wrong, but that really surprises me. I don't think that's light burn. I have had plants up to 2-3" below diodes with no burn (assuming reasonable ppfd <950). I believe that tracks the experiences of @Mañ'O'Green as well.

And, as mentioned, there is an app that some use to allow a smartphone to act as a par meter.

 

[jdm61]

I am not saying you are wrong, but that really surprises me. I don't think that's light burn. I have had plants up to 2-3" below diodes with no burn (assuming reasonable ppfd <950). I believe that tracks the experiences of @Mañ'O'Green as well.

And, as mentioned, there is an app that some use to allow a smartphone to act as a par meter.

It looks like a deficiency but its only on the top leaves. I just got one of those apps, but it only seems to work at like dead center. Plus, you can't read it very easily because it is being blasted with artificial sunlight. It showed slightly over 1000 at 12 inches and in the 680-800 range at 15-18

 

[GreenBean]

No, because that would mean that I would have to buy a light meter. Dont have the spare cash for such things.

You could just use Photone if you have an iPhone. Or for Android, the Migro dude just reviewed an Android app called "PPFD APP" I believe. They are very close to being as accurate as a meter now. 98% accuracy when compared to a meter, if I recall.

EDIT - I see you already tried an app. I use Photone and it works well and reads well across the entire tent. Photone has a hold feature if you tap and hold the screen you can hold the reading to make it easier to read.

 

[man10101]

i use a UNI-T ut383 as my light meter
its the one migro recommends
they only cost about £17 and if u multiply the reading by 0.014 its pretty much the same as a $500 apogee sensor

 

[CannabisMingus]

The apogee will be more accurate but it's pole vaulting over mouse turds at that point. The UNI-T and other work arounds are plenty accurate for cannabis cultivation.

 

[jdm61]

You could just use Photone if you have an iPhone. Or for Android, the Migro dude just reviewed an Android app called "PPFD APP" I believe. They are very close to being as accurate as a meter now. 98% accuracy when compared to a meter, if I recall.

EDIT - I see you already tried an app. I use Photone and it works well and reads well across the entire tent. Photone has a hold feature if you tap and hold the screen you can hold the reading to make it easier to read.

I have the Phtone app. Thanks for the info about the hold feature.