[Scotty Real]

Thanks for sharing the knowledge. I get what you’re saying. Sometimes I over simplify thing to make them easy to understand and explain. Thanks for the clarification.

[jmystro]

Daily doesn’t mean a 24 hour period. It’s the amount of photons a plant needs/uses during it’s daily light cycle. Petioles tend to have varying degrees of ‘limp’ when a plant’s reached it’s DLI.

[stanm]

Sometimes certain plants don’t agree with the PPFD and DLI chart. It’s a good starting point but I have the phone ap and the diffuser on an iPhone. Some plants want less than the charts call for so I still keep an eye on the leaves. It happens in my 2×4 so I think they get more reflection because it’s only 2’ wide.

[battlemorph]

Don’t they want just enough light so they’re just before the leaf praying stage and are more flat? Or is that not reliable?

[BePennjier]

I don’t get it. Daily here means from
sunrise to sunrise, on Earth that’s about 24 hours. This way you
compensate for different lenghts of the night cycle and can compare
amounts of energy.
You have the actual DLI that’s what you put on a
plant (or area), this is calculated from your PPFD
and you have the
max DLI a plant can take that’s tested experimentally in labs by
scientists.
Max DLI means there is no improvement in yield and/or
quality OR you’re starting to even hurt them if you put more on the
plant. That’s were max DLI numbers for different plants come from
(like ~12 for salad, ~26 for basil, ~35 for broccoli). In a tent your acutal DLI = potential DLI. outdoors potential DLI depends on season and latitude and on a cloudy or rainy day your actual DLI can be a fraction of your potential DLI. So DLI can mean both the amount of light your plants get as well as the amount they can take.

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[jmystro]

DLI is hours of sunlight per day a specific plant absorbs. DLI is not some universal plant metric. Maybe 16, maybe 20. Every plant is different. No plant absorbs light 24 hours of light a day, even Rudy up north has a DLI.

[BePennjier]

1. except for the 24h thing you’re pretty much saying what I said, or not?
2. the 24h thing: DLI is not ‘hours of light per day’ it’s ‘amount of light per day’ that’s why it’s called Daily Light Integral and not Daily Light Hours. If it were hours of light per day you wouldn’t need an integral. That’s litteraly the first sentence in the wiki article: ‘…number of photosynthetically active photons…’ (or amount of light not hours of light) ‘…that are delivered to a specific area..’ (a square meter) ‘…over a 24-hour period.’ (or daily). how many hours the light was on this day doesn’t tell you how bright the light was. of course no plant takes up light during night but that’s not what DLI means or says. it’s a mathematical compensation. you’re right it’s not a universal plant metric, it’s a human metric to quantify and talk about the light energy that -depending on context- is available to a plant (actual DLI) or a plant can use before it shuts down (max DLI a plant can take) within a daily period. and there a charts where you can look up what kind of DLI you can expect for a specific place for all seasons which is incredible usefull for commercial farmers on the fields and in the greenhouses and thats where it comes from. indoors DLI doesn’t really matter to me, I only have the light I have and there has never been a cloudy day in my tent. when you take the D out od DLI you get PPFD which is ‘amount of light over an area per second’ (I know I don’t have to explain this to you, sorry) which since I don’t have clouds in my tent is a better metric for me to use although they are the same messurment just over different time periods.

(and another sorry: my texts tend to get longer when I smoke, but I love this kind of nerding out even if I’m wrong, which in this case I don’t think I am..yet🤓)

[lightning93]

I have wyse cams in both tents. @jmystro completely correct in what he said. I am on my 3rd grow and I have always seen when DLI is reached the leaves start to droop a little. Don’t confuse this with over watering or under watering. I made that mistake and over watered.

• This reply was modified 2 months ago by  lightning93.