Is this light burn or something else?

[EH40veg]

Any help would be appreciated not sure if it’s light burn or a deficiency but tips are looking a bit pale / burnt. Got them under a 720w led but it’s dimmed to 250ws about 25 inches away and feeding them canna coco a&b about 1.0ec with the rhizotonic and cannazym once per week. 3rd image is on a different plant, leaf’s at bottom that’s probably something different.

 

[Roy O'Bannon]

They look light colored, like they are either too wet or hungry imo. I would immediately overfeed them

 

[EH40veg]

They look light colored, like they are either too wet or hungry imo. I would immediately overfeed them

Thanks mate will give them a good feed in the morning come lights on and hopefully do the trick.

 

[ec121]

PPFD, man. Just use that Photone app for iOS. It's accurate enough for growing. For the diffuser, you can just cut a small blank portion of a grocery store receipt and place it over the front facing camera. Just turn off the oscillating fans so it doesn't blow off the phone/iPad.

What is your runoff EC? Never adjust your inflow EC without referencing your runoff EC.

Take a picture with the lights off using the flash from your phone or (room lighting) and you will see the leaves will likely be quite green. You can do that during their dark cycle if you want because it's in veg and doesn't matter if it gets briefly disrupted.

Also, you're letting your coco get too dry. You're starting to treat it like soil again by going by weight to feed. You can water coco to stay at pretty much 100% saturation and the roots will still get oxygen if the coco was prepped properly, you have proper drainage, and ensured that you won't have a stagnant spot in the center that can become hypoxic.

You're not feeding to give it more water; you can literally grow in coco like soil and water once or twice a week, but that's not optimal and using soil would work better if you're going to treat coco like it's soil.

You're feeding it at least once daily to keep the EC of the rhizosphere consistent and replenish the water with cool, fresh oxygenated water. You have to think of growing in coco like it's DWC. In DWC, the roots are 100% in water at all times.

With regard to your question about runoff in your other thread, you can get as much runoff as you like, so long as it is at least 10%. Most people just prefer to cut down on waste by only giving it as much as is needed to maintain a consistent rhizosphere.

If one is fertigating once a day, more runoff is needed to maintain a consistent rhizosphere; if one is fertigating six times a day, then less runoff is needed to maintain a consistent rhizosphere, but in either case, at least 10%.

 

[EH40veg]

PPFD, man. Just use that Photone app for iOS. It's accurate enough for growing. For the diffuser, you can just cut a small blank portion of a grocery store receipt and place it over the front facing camera. Just turn off the oscillating fans so it doesn't blow off the phone/iPad.

What is your runoff EC? Never adjust your inflow EC without referencing your runoff EC.

Take a picture with the lights off using the flash from your phone or (room lighting) and you will see the leaves will likely be quite green. You can do that during their dark cycle if you want because it's in veg and doesn't matter if it gets briefly disrupted.

Also, you're letting your coco get too dry. You're starting to treat it like soil again by going by weight to feed. You can water coco to stay at pretty much 100% saturation and the roots will still get oxygen if the coco was prepped properly, you have proper drainage, and ensured that you won't have a stagnant spot in the center that can become hypoxic.

You're not feeding to give it more water; you can literally grow in coco like soil and water once or twice a week, but that's not optimal and using soil would work better if you're going to treat coco like it's soil.

You're feeding it at least once daily to keep the EC of the rhizosphere consistent and replenish the water with cool, fresh oxygenated water. You have to think of growing in coco like it's DWC. In DWC, the roots are 100% in water at all times.

With regard to your question about runoff in your other thread, you can get as much runoff as you like, so long as it is at least 10%. Most people just prefer to cut down on waste by only giving it as much as is needed to maintain a consistent rhizosphere.

If one is fertigating once a day, more runoff is needed to maintain a consistent rhizosphere; if one is fertigating six times a day, then less runoff is needed to maintain a consistent rhizosphere, but in either case, at least 10%.

Cheers mate just seen your reply but made a different post, what is a good ppfd for veg I’ll go do that now with the paper if I can find a blank piece.

Earlier on my EC in was 1.2 and out was 1.3 so think it’s ok, but yeah mate I had been keeping it more damp but I had nip away for 2 days so got a little drier than I would have wanted.

After I took this pic I fed them to runoff again but they don’t seem to have reacted much.

 

[EH40veg]

Cheers mate just seen your reply but made a different post, what is a good ppfd for veg I’ll go do that now with the paper if I can find a blank piece.

Earlier on my EC in was 1.2 and out was 1.3 so think it’s ok, but yeah mate I had been keeping it more damp but I had nip away for 2 days so got a little drier than I would have wanted.

After I took this pic I fed them to runoff again but they don’t seem to have reacted much.

Just used that app there but used a piece of a4 paper not sure if that’s ok, but it says around 380 ppfd.

 

[ec121]

Cheers mate just seen your reply but made a different post, what is a good ppfd for veg I’ll go do that now with the paper if I can find a blank piece.

Earlier on my EC in was 1.2 and out was 1.3 so think it’s ok, but yeah mate I had been keeping it more damp but I had nip away for 2 days so got a little drier than I would have wanted.

After I took this pic I fed them to runoff again but they don’t seem to have reacted much.

You want to be between 280-550 in veg, and 650-1500 in flower (above 1000, CO2 is necessary). If you want to push toward the high ranges, then everything needs to be perfect - nutrition, CO2, VPD, so it's best to stay in the middle and go from there.

1.2 inflow and 1.3 outflow is great. Just keep plugging away or bump to feeding twice a day.

Just used that app there but used a piece of a4 paper not sure if that’s ok, but it says around 380 ppfd.

Depends on the weight of the paper. A grocery receipt is best because they use the cheapest paper (at least in the US) so it's really thin. But that's good if it's right at canopy level and similar over the other ones, but you could bump it a hair if you want (by lowering the light).

Post a pic of the plant without the grow lights on.

 

[EH40veg]

You want to be between 280-550 in veg, and 650-1500 in flower (above 1000, CO2 is necessary). If you want to push toward the high ranges, then everything needs to be perfect - nutrition, CO2, VPD, so it's best to stay in the middle and go from there.

1.2 inflow and 1.3 outflow is great. Just keep plugging away or bump to feeding twice a day.



Depends on the weight of the paper. A grocery receipt is best because they use the cheapest paper (at least in the US) so it's really thin. But that's good if it's right at canopy level and similar over the other ones, but you could bump it a hair if you want (by lowering the light).

Post a pic of the plant without the grow lights on.

No worries mate so around 380-400 should be ok could maybe lower the light slightly like u said. But would probably just keep it 1000 or under then as not got c02.

Thanks mate will keep feeding away at 1.2 just now then until see a change in the runoff. It was quite thick tbh I’ll get a receipt or something in the morning and a photo with the lights off then as well they go off in about 3/4 hours.

 

[EH40veg]

No worries mate so around 380-400 should be ok could maybe lower the light slightly like u said. But would probably just keep it 1000 or under then as not got c02.

Thanks mate will keep feeding away at 1.2 just now then until see a change in the runoff. It was quite thick tbh I’ll get a receipt or something in the morning and a photo with the lights off then as well they go off in about 3/4 hours.

Here’s a pic I took with the lights off

 

[Roy O'Bannon]

Here is a light chart. Regular paper is fine. I think there is a tutorial in the app. I just use a strip like they suggest. The app is calibrated for specific paper and specific phones. If you use thinner paper more light will come through and throw off your readings.

 

[1212ham]

You want to be between 280-550 in veg, and 650-1500 in flower (above 1000, CO2 is necessary). If you want to push toward the high ranges, then everything needs to be perfect - nutrition, CO2, VPD, so it's best to stay in the middle and go from there.

1.2 inflow and 1.3 outflow is great. Just keep plugging away or bump to feeding twice a day.



Depends on the weight of the paper. A grocery receipt is best because they use the cheapest paper (at least in the US) so it's really thin. But that's good if it's right at canopy level and similar over the other ones, but you could bump it a hair if you want (by lowering the light).

Post a pic of the plant without the grow lights on.

Why would a grocery receipt be better than the paper specified by the app?

 

[ec121]

Why would a grocery receipt be better than the paper specified by the app?

When I bought the app it was called Korona (which they changed the name in 2020 to Photone) and to my recollection there were no tutorials in the app and all I heard was to use the thinnest copy paper and I use 120gsm copy paper. I now see it recommends 80gsm, but can't find specific info on which brightness to use. I see a post saying 96 brightness is most accurate, but that is not from the app developer.

Sorry for the misinformation, guys, and thanks for the correction.

 

[EH40veg]

When I bought the app it was called Korona (which they changed the name in 2020 to Photone) and to my recollection there were no tutorials in the app and all I heard was to use the thinnest copy paper and I use 120gsm copy paper. I now see it recommends 80gsm, but can't find specific info on which brightness to use. I see a post saying 96 brightness is most accurate, but that is not from the app developer.

Sorry for the misinformation, guys, and thanks for the correction.

Hey mate still got the light at 400 just now, but 3 of the plants are looking a bit droopy, feeding 500mls a day at 1.3EC but that’s giving me more than 20% runoff going to back it down slightly so getting a bit less.

First photo is 3 I’m talking about, 2nd is all of them other 5 looking better.

 

[ec121]

Hey mate still got the light at 400 just now, but 3 of the plants are looking a bit droopy, feeding 500mls a day at 1.3EC but that’s giving me more than 20% runoff going to back it down slightly so getting a bit less.

First photo is 3 I’m talking about, 2nd is all of them other 5 looking better.

I have had indicas that have looked like that. They always have grown out of it later in veg with no changes on my part. How do you they look after the lights have been on 8-10 hours?

The one in the middle of the eight plant pic is the only one I'd keep an eye on if they were mine. Also, what are you doing to keep runoff from collecting around the bottom of the plant?

Are you running a microbial or running H2O2?

 

[MissinThe90’sStrains]

It’s very important to keep the pot raised and keep the plant from “drinking” that runoff. If the pot sits in the runoff, all those salts that you’ve just run out of your medium are going to wick right back up in there. When the water gets used up, those extra salts will just concentrate in your medium. This can cause imbalances and/or lockouts.

 

[medidedicated]

Hmm. So you ended up testing each by itself and got 1.2 in 1.3 ec out? Thats good. Sucks you still have that droop but for what its worth I actually recall getting growth like that from too much light.

I almost said this on your last thread if I recall your profile correctly, I mix names forget whos who at first. I think so I recognize the runoff setup lol.

Those lights are reallllllly strong. Take phone app ppfd readings with grain of salt. I dont even use it anymore I go by signs.

My light is 250w and turned on max 2 feet high or higher torched my plants. Sooo happy to see them turn around letting up the light. Turned on 25% 2’ high or lil more.

Im noticing theyre more sensative to light positioning in veg than flower. Real sensative I only go around 300ppfd lil less. I thought more is better but nope.

Those plants are still small too reminds me of when I scortched them at that size. Try dimming them more and/or raising it, to a counter intuitive degree so they can heal.

Theyre not seedlings so a little stretch is fine. If that dont fix it I got nothing else. Some times people just get issues none of us can figure out but hopefully it resolves.

 

[medidedicated]

I forget if you rinsed and buffered coco I think you used ready to use but rinsed and buffered more and transplanted into that right? If so beats me, water log can droop leafs.

Again like I said on other thread I rinse and buffer mine so its easier to figure out issues. Heres my veg plants scorched and mostly healed. Seedlings not drooping. No droop anywhere infact.

 

[medidedicated]

Dug up what I was talking about. My last memory of droopy plants and leaf issues due to the light. Notice the super purple leaf stems for the age of the leaf.

It got way better but sadly no pics I tossed it realizing I had one too many things going on.

Reminds me of your plants a bit but yours look fine atm. Just a tip if they get worse as Ive seen us get you up to date with everything its pretty simple dtw coco.

 

[Delps8]

Hey mate still got the light at 400 just now, but 3 of the plants are looking a bit droopy, feeding 500mls a day at 1.3EC but that’s giving me more than 20% runoff going to back it down slightly so getting a bit less.

First photo is 3 I’m talking about, 2nd is all of them other 5 looking better.

At 400µmol, your plants are getting about 50% of the light that they can use to achieve their genetic potential.

When I tested Korona/Photone back in 2021, the programmer didn't specify the weight of the paper that's used as a diffuser. I discussed that with him (email) and I think he went with #22 paper. After testing Photone, I found it to be 16% high and, as a result, recommend it only after other options have been explored.

If Photone is reading 16% high for you, your plant is getting about 350µmol. That's seedling/early veg levels. You can go as low as 64µmol for cannabis so it won't die at 350 but your crop will be modest.

Re. the chart from Photone. When I asked the programmer about the sources of information for the chart, he directed me to the footnotes on the page. There were none. I also asked him about recommendations of autos and he said that they considered autos to be "always in veg".

Since 2021, they have added a septette diagram for autos.

The only values that are close to being optimal for crop yield and quality are in some of the later weeks of flower. I say that because I grow my plants "according to research" and, in the later weeks of veg, my grows max out at the DLI's that GLM.com recommends. Other than that, their recommendations are not supported by what we know is the best approach to allowing a cannabis plant to thrive.

Cannabis is a light whore loves light. I've seen no other site that recommends dropping DLI after going into flower. Other sites and most grow light manufacturers recommend increasing light levels and, overall, their recommendations are very conservative. By that I mean, if you follow their recommendations you will get a good crop. If you want an excellent crop, you should feed your plants as much light as they can handle.

A grower will lose more yield in their crops by not giving their plants light than they do by giving their plants too much light.

A fact - it's very hard to harm a cannabis plant by giving it too much light. I've had that happen a few times, some times because I push my plants and a couple of times due to equipment failures, but in all cases (except one) within a few minutes of my realizing that the light levels were too high, the plant had returned to its normal shape (the leaves uncurled). The one case where the plant didn't return to its normal shape was a cola that got bent about 2" from the top. Not a big deal.

The other side of the spectrum (sorry) is that growers don't know to or refuse to give their plants more light so they "leave money on the table".

This chart is from the cited source (copy attached)


Simply put, the change in yield between an average of 600µmol and 900µmol will be in the range of 5.2+4.9+4.7+4.5+4.3≈20%. Some growers would like to have an extra 20% yield but, I'll be the first to agree that cannabis will provide a good yield at moderate light levels. On the other hand, if you're willing to turn up the dimmer a bit, you'll end up with not only a larger crop but, if you give your plants a lot of light from the jump, you'll get plants that are much easier to work with.

Roll back to seeing plants that are tall and slender, with not a lot of leaves and lots of internodal space. Those are classic symptoms of plants that aren't being fed well. On the other hand, a cannabis plant that gets a lot of light will be more "full" - lots of branches and leaves with short internodal space. That will, on one hand, tend to give you a more uniform quality between the top and bottom buds but the shorter plant is much easier to work with than a tall, gangly plant.

I strongly recommend that growers watch one or both of these videos:

Westmoreland is a PhD candidate under Bruce Bugbee and his research comports with and builds on existing research.

So, yeah, your plants will grow at 400µmol (but probably lower) but you'll have much better results if your plants are getting twice that amount of light (or more).

 

[Jjgrow420]

How's your temps? Cold rooms + led = floppy yellowing plants.