Mine are similar that are in direct path of light. What is the recommended distance?

Habosabin said:

Mine are similar that are in direct path of light. What is the recommended distance?

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The recommended distance is whatever is high enough to evenly light the edges of the tent, so that depends on the size of your tent as much as anything. Then there is the dimmer. The recommendation is not for distance but for light level. Sometimes I think everyone forgets that. Anyway, in my case the minimum distance for coverage needs to be a good 12 inches higher than I can get it now. And I don't want to replace the grow tent yet again during flowering. So I turn the dimmer down to give me a PAR reading of 1000 or less.

Generally when I'm using to much light the stems on fan leafs are red on top and green on bottom. Red on both sides is generally over feeding. Since your stems are green I'd say Its not getting enough nutrients to process the light, or enough water up top to encourage transpiration. I doubt it's to much light, could be.. But I'd say it's a nutrient uptake issue and ur just pushing the growth, so then the tallest buds get damage.

Cashmeh said:

Generally when I'm using to much light the stems on fan leafs are red on top and green on bottom. Red on both sides is generally over feeding. Since your stems are green I'd say Its not getting enough nutrients to process the light, or enough water up top to encourage transpiration. I doubt it's to much light, could be.. But I'd say it's a nutrient uptake issue and ur just pushing the growth, so then the tallest buds get damage.

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Hmm. I'm wondering - there are tall colas sticking up well above the canopy, but just off the direct light at the edge. One, more away from center, looks perfect. Frosty, green, swollen, growing. The other looks really good, except the fan leaves. On various colas, the only leaves that I can see with stress are the fan leaves on the top layer of canopy. I think with all four plants - so there is definitely a light component here. I turned the lights down a bit more today. Way down to under 1000 PPFD at center, more like 400 at best at the edges now. Seems to have helped as I see renewed growth, though no improvement in those leaves yet. Just refilled the reservoir with new (late bloom) nutes yesterday, so I'll see if things improve, leaf-wise. First time I've seen unhealthy leaves this whole grow.

EC on input around 1100 now.

phxazcraig said:

Hmm. I'm wondering - there are tall colas sticking up well above the canopy, but just off the direct light at the edge. One, more away from center, looks perfect. Frosty, green, swollen, growing. The other looks really good, except the fan leaves. On various colas, the only leaves that I can see with stress are the fan leaves on the top layer of canopy. I think with all four plants - so there is definitely a light component here. I turned the lights down a bit more today. Way down to under 1000 PPFD at center, more like 400 at best at the edges now. Seems to have helped as I see renewed growth, though no improvement in those leaves yet. Just refilled the reservoir with new (late bloom) nutes yesterday, so I'll see if things improve, leaf-wise. First time I've seen unhealthy leaves this whole grow.

EC on input around 1100 now.

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Yea I'd say your high fert method works well for veg, but once flower you might have to do it like everyone else does it. I don't do drip or know why timers and runoff are set certain ways.

Id say it's not able to pull up nutrients due to high flow rates, so alls well if it's growing slow. But when you push the growth rates, you see problems at the spots receiving the most light.

Its like adding Co2 when someone has a deficiency. By increasing your lights, your pushing it to hard and there's not enough of something to complete normal growth.

Hell I ran my res out of Magnesium cause I forgot to add calmag and just kept adding ph up and down for calcium. I have some spots on my upper fan leafs that are closest to the light, but the edges of the leafs are not burnt. My stems stay red due to my hids. For me, it's very hard to burn my plants with light. Usually it's something else I'm doing wrong. I do keep them a few feet from the light though.

Idk man, wish I knew coco, but again thats why I'm here lol..

Raise ur light, if not possible top them off or bend the plant over and tie it off.

Edinburgh said:

Raise ur light, if not possible top them off or bend the plant over and tie it off.

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I cannot raise the light further.

6 weeks into flowering and you're suggesting topping? I think it's too late for that.

I've turned the power down on the light, helping the center and sacrificing the edges.

Cashmeh said:

Yea I'd say your high fert method works well for veg, but once flower you might have to do it like everyone else does it. I don't do drip or know why timers and runoff are set certain ways.

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You're suggesting I feed less often? Right now I'm actually feeding more in an effort to keep salts from building up. (That's why I watch the EC of the runoff.) It seems to be working, though at the cost of going through an amazing amount of fertilizer. This morning I took 7 buckets of runoff (EC anywhere from 1300 to 2000) that built up over last week and dumped them on various plants outside - trees, bushes, flowers, whatever.

Compared to veg, it seems like the flower stage is just like my soil grow, except I'm thinking the colas are going to be much bigger. It's a bit hard to tell here, because the strain must be taken into account. I'm growing Sour Diesel this time, and it's said to have an 11-week flowering stage, so seems slow.

Cashmeh said:

Id say it's not able to pull up nutrients due to high flow rates, so alls well if it's growing slow. But when you push the growth rates, you see problems at the spots receiving the most light.

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I wish I knew more about growing. I've read a LOT about cannabis since it was legalized in Colorado, but never about growing it until last year.

I'm not trying to push growth rates, just trying for healthy plants. This is by far the worst thing I've seen with the plants this grow, but it is limited as well - only top fan leaves directly under light at a distance of 12-14 inches. This light should have at least 24 inches clearance, if not 36.

Cashmeh said:

Its like adding Co2 when someone has a deficiency. By increasing your lights, your pushing it to hard and there's not enough of something to complete normal growth.

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Again, only a few parts of the plants directly under the lights show issues. The growth below those scorched leaves on the same cola look fine. The parts of the plants that had the right amount of light around the edges look tremendous. Other than the 'sunburn', I've had a small bit of tip burn, which I'm addressing by lowering EC (and increasing runoff).

Cashmeh said:

Hell I ran my res out of Magnesium cause I forgot to add calmag and just kept adding ph up and down for calcium. I have some spots on my upper fan leafs that are closest to the light, but the edges of the leafs are not burnt. My stems stay red due to my hids. For me, it's very hard to burn my plants with light. Usually it's something else I'm doing wrong. I do keep them a few feet from the light though.

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I'm just starting to learn about what red stems mean. Care to explain?

Cashmeh said:

Idk man, wish I knew coco, but again thats why I'm here lol..

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Coco - now that I'm most of the way through a grow, I'd say this. The only complicated part seems to be figuring out how much cal/mag is needed, though that's probably my ignorance showing. I don't know how much is really needed, especially late in the grow, but it eats a lot of my EC budget that might otherwise have been used for nitrogen.

Compared to soil, it's far easier to water and not overwater, which I appreciate. It will be interesting to open the pots at the end and see the root growth.

Because it is not soil, I had to unlearn some things, and I've had to set up and automated watering system. That also forced me to set up an automated drainage system. All that forced me to learn about pH and nutes as well, which learning process is continuing.

Since I posted those pics, the problem has mostly worsened. Lots of the affect leaves are pretty yellow now. I'd put that down mostly to flowering, but all the yellowed leaves are the top layer under the brightest area. Oh well, because of the light clearance issue I've had to compromise, and this just seems the inevitable result.

In looking closely at the affected leaves today, I saw one that seals the deal for me in terms of explaining this as light stress. One of the leaflets on an upper fan leaf that is obviously quite affected has been partially shielded under another leaflet from a nearby cola. That leaflet is split right down it's center - the shaded part looks healthy and green while the other half is yellowed and spotted. I'll have to get a pic of it.

phxazcraig said:

In looking closely at the affected leaves today, I saw one that seals the deal for me in terms of explaining this as light stress. One of the leaflets on an upper fan leaf that is obviously quite affected has been partially shielded under another leaflet from a nearby cola. That leaflet is split right down it's center - the shaded part looks healthy and green while the other half is yellowed and spotted. I'll have to get a pic of it.

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Start to lower the EC of the feed but about 15 percent each week moving forward. About the start of week 7 they will drink less water each time they are getting watered and the light needs will start to drop off the end of week 6. Week 7 they will bulk and week 8 as well. If you are under budget lights run the plant an extra week.

phxazcraig said:

You're suggesting I feed less often? Right now I'm actually feeding more in an effort to keep salts from building up. (That's why I watch the EC of the runoff.) It seems to be working, though at the cost of going through an amazing amount of fertilizer. This morning I took 7 buckets of runoff (EC anywhere from 1300 to 2000) that built up over last week and dumped them on various plants outside - trees, bushes, flowers, whatever.

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So im not gonna be able to give you advice on how to feed because ive never ran coco. I have just seen enough posts on it to know understand the overall concept. So when you first posted your growth rates thread, i said it had to be caused by high run off. Then you agreed, and i was shocked that I was right lol. But in my head, you were doing things differently, which is why you had better veg results. Now that your in flower, and you still have the high feed rates, or whatever it is, i really dont undestand coco, whatever your doing differently than most, well it doesnt work for flower unlike veg.

I would assume that certain nutrients during flower need a longer retention time with the roots. Yet for veg, those nutrients can be uptaken even under high flow rates.

As for me suggesting you feed it less, all I can relay is that you want almost 0 run off, like the guy who taught me, taught others, and I remember him telling them to reduce their run off, like he said if you reduce it, you dont have to monitor it as much, mainly focus on input feed. Perhaps im wrong, but id say however everyone else on here is doing it, id do it like them. I would suggest your method for vegging them in coco is better than most, yet as for the flower they got ya on that.

phxazcraig said:

Compared to veg, it seems like the flower stage is just like my soil grow, except I'm thinking the colas are going to be much bigger. It's a bit hard to tell here, because the strain must be taken into account. I'm growing Sour Diesel this time, and it's said to have an 11-week flowering stage, so seems slow.

I wish I knew more about growing. I've read a LOT about cannabis since it was legalized in Colorado, but never about growing it until last year.

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Ironically I started growing in February of last year too, little over a year. I started with dwc, then rdwc. Ive never grown anything inside or outside in dirt or coco. .only water. I would suggest hanging out here and keep doing what your doing. Hit up @Dirtbag for some flower coco help, he makes beautiful plants and Im sure he uses coco. Lucky for you, lots of people here do it, its just if you apply it or not, or how you apply their logic. You seem way smarter than me so im sure you will pull the info out of someone eventually.

phxazcraig said:

I'm not trying to push growth rates, just trying for healthy plants. This is by far the worst thing I've seen with the plants this grow, but it is limited as well - only top fan leaves directly under light at a distance of 12-14 inches. This light should have at least 24 inches clearance, if not 36.

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Well when you go coco, your pushing growth rates in my eyes. Anytime you have to feed it nutrients, your gonna get hella boom. Guess its just my train of thought.

phxazcraig said:

Again, only a few parts of the plants directly under the lights show issues. The growth below those scorched leaves on the same cola look fine. The parts of the plants that had the right amount of light around the edges look tremendous. Other than the 'sunburn', I've had a small bit of tip burn, which I'm addressing by lowering EC (and increasing runoff).

I'm just starting to learn about what red stems mean. Care to explain?

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So if your fan leaf stems are red, and your stalk has red veins, its a sign of overfeeding, Some plants have different color genetics though, so ya gotta be carefull. All of my strains ive ever grown have green stems at the beginning. Now once I lower the light and start pushing the growth rates, the top fan leafs will have the top side of the stems red, but underneath the stems they will be green, and my main stalk will be green. To me this is normal and what I want. Now when I give them too much light the fan leafs become brittle looking, and start to wilt on the edges, while the jagged edges slowly turn yellow. When the light burns the leafs the damage works its way in, starting at the tips getting the least amount of transpiration and are the thinnest. Ill try to find a picture if I can, I actually need to lower my lights about a foot after this grow. I have yet to get any light burn and im depressed. I want a bit of it at the top, that way I know im pushing growth rates. Ill find a pic after this comment.

phxazcraig said:

Coco - now that I'm most of the way through a grow, I'd say this. The only complicated part seems to be figuring out how much cal/mag is needed, though that's probably my ignorance showing. I don't know how much is really needed, especially late in the grow, but it eats a lot of my EC budget that might otherwise have been used for nitrogen.

Compared to soil, it's far easier to water and not overwater, which I appreciate. It will be interesting to open the pots at the end and see the root growth.

Because it is not soil, I had to unlearn some things, and I've had to set up and automated watering system. That also forced me to set up an automated drainage system. All that forced me to learn about pH and nutes as well, which learning process is continuing.

Since I posted those pics, the problem has mostly worsened. Lots of the affect leaves are pretty yellow now. I'd put that down mostly to flowering, but all the yellowed leaves are the top layer under the brightest area. Oh well, because of the light clearance issue I've had to compromise, and this just seems the inevitable result.

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So as for what to do now. Id start from scratch with a flower feed rate thread for coco. Or study a few. Good suggest is hit that search bar, member name "Aquaman" Search Coco Feed Rates, or something similar. He flooded the forums with everything you need to know, all he did was repeat himself over and over on everyone who needed help.

As for looking at ur pics above of the leafs, this is the first i seen it lol. Yea thats not light burn, thats nutrient uptake issues. Its not getting something, id compare it to a deffeciency photo chart.

I may be wrong but it could be cal mag deficcancy

Show pics of the plant tops and the buds to see what's going on

And Aquarman is the man lol my hero haha where are you buddy ain't seen u about

Dunno how well you can zoom in. But the white widow in the middle the light burn really shows. the middle of those upper leafs have 0 deficiencies. I mean someone could say that is nutrient burn, but I can then show them pictures of the fan leafs at the bottom and middle that look perfect, with green stems all the way around. The red stems on top are really bright. but the underbelly is green, so I know these plants are not overfed.

Now tthese plants did get root rot right about this time. It was my first grow.

Here are some better pics from today.

Here is one of the big colas right under the light - less than 12 inches, but just at the edge of the light.

Notice the shaded part of the leaf on the right? Color there is almost normal.


Here is a closer look.


OK, those are leaves under lights that are just too close. But here are buds off to the sides:
Far right side.


Right front.



Back left, somewhat close to the light, but not directly under:

Here is a closer crop of one of the buds. I think it's looking ok.

phxazcraig said:

I cannot raise the light further.

6 weeks into flowering and you're suggesting topping? I think it's too late for that.

I've turned the power down on the light, helping the center and sacrificing the edges.

Click to expand...

Bend the colas and know Indica leaning hybrids dont need tropical light intensity. I set my SF4000 to 28 inches and 55% on the dimmer. If I go higher in light intensity the center of the grow suffers. I dont like this light because the center is too strong compared to the edges. The canopy has to be even or the center buds bake!! This is 1 banana kush auto starting the 6th week of flower.

phxazcraig said:

You're suggesting I feed less often? Right now I'm actually feeding more in an effort to keep salts from building up. (That's why I watch the EC of the runoff.) It seems to be working, though at the cost of going through an amazing amount of fertilizer. This morning I took 7 buckets of runoff (EC anywhere from 1300 to 2000) that built up over last week and dumped them on various plants outside - trees, bushes, flowers, whatever.

Compared to veg, it seems like the flower stage is just like my soil grow, except I'm thinking the colas are going to be much bigger. It's a bit hard to tell here, because the strain must be taken into account. I'm growing Sour Diesel this time, and it's said to have an 11-week flowering stage, so seems slow.

I wish I knew more about growing. I've read a LOT about cannabis since it was legalized in Colorado, but never about growing it until last year.

I'm not trying to push growth rates, just trying for healthy plants. This is by far the worst thing I've seen with the plants this grow, but it is limited as well - only top fan leaves directly under light at a distance of 12-14 inches. This light should have at least 24 inches clearance, if not 36.

Again, only a few parts of the plants directly under the lights show issues. The growth below those scorched leaves on the same cola look fine. The parts of the plants that had the right amount of light around the edges look tremendous. Other than the 'sunburn', I've had a small bit of tip burn, which I'm addressing by lowering EC (and increasing runoff).

I'm just starting to learn about what red stems mean. Care to explain?

Coco - now that I'm most of the way through a grow, I'd say this. The only complicated part seems to be figuring out how much cal/mag is needed, though that's probably my ignorance showing. I don't know how much is really needed, especially late in the grow, but it eats a lot of my EC budget that might otherwise have been used for nitrogen.

Compared to soil, it's far easier to water and not overwater, which I appreciate. It will be interesting to open the pots at the end and see the root growth.

Because it is not soil, I had to unlearn some things, and I've had to set up and automated watering system. That also forced me to set up an automated drainage system. All that forced me to learn about pH and nutes as well, which learning process is continuing.

Since I posted those pics, the problem has mostly worsened. Lots of the affect leaves are pretty yellow now. I'd put that down mostly to flowering, but all the yellowed leaves are the top layer under the brightest area. Oh well, because of the light clearance issue I've had to compromise, and this just seems the inevitable result.

Click to expand...

Dude, save money and fix your problem by…..ie Reservoir capacity is 25 gallons, set feed strength, as the reservoir depletes, top off with Ph water only, when you have added 25 gallons of top off or the equivalent of your reservoir size, or 1 week of time expires, make a new batch!!! Topping off your reservoir with the same strength feed solutions is costly and problematic! Simply adding PH water will fix your ills. Been there got the t- shirt! Your plants will tell you if you are not feeding enough. Coco coir starts out nutrient free however, salt (nutrient) build up is inevitable. You are suffering from over fertilization and curing the problem by increasing the fertigation doses!! Simple fix! By the way, my feed is 800ppm and runoff 1500 ppm using this method. My start was 1200. Save money by topping off.

phxazcraig said:

Here are some better pics from today.

Here is one of the big colas right under the light - less than 12 inches, but just at the edge of the light.

Notice the shaded part of the leaf on the right? Color there is almost normal.
View attachment 1233213

Here is a closer look.
View attachment 1233214

OK, those are leaves under lights that are just too close. But here are buds off to the sides:
Far right side.
View attachment 1233215

Right front.

View attachment 1233216

Back left, somewhat close to the light, but not directly under:
View attachment 1233217

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I wouldnt worrie to much they are not to far from harvest are they?
They still look good
Leaves do go like shit the last few weeks.

Can seen slight nute burn tips tho..
In coco the say you want rub off 0.2-0.6e.c more then in, that's 100-300ppm
Maybe they need less need feed now they close to harvest.
I only flower for 8 weeks I flush from end of 6th week for 2 weeks and the go yellow and shit my bud usually explode in the flush I find
If your gonna flower longer drop the feed maybe as near the end you ment to or maybe knock 100ppm/0.2e.c off your feed and replace it with 100pm/0.2e.c calmag to see if that helps the rust spots and yellowing a but maybe u have soft water?

Check the run off e.c is gonna give you a good idea what's going

Like others said maybe gently lean the top buds to the side a tad use string you don't want the be putting bends/creases in them stems this late

Try tying , how u spell it lol ? Try tying the light to the top of the the tent I find that most light hangers/strings when the pulled up ton the max their still like 4-6" between the room and the light as the hangers plastic bit it wasting that little space, using rope to the the actual light to the top of the tent I can get few more inches




I had that 2-Tonning before I upped my need it went away, it's a to think it was something do with calmag it was a strain called pineapple chunk had it on few grows new strain not had it, but with the pineapple chunk upping my feed it went away

If your 6 weeks into flower on a 8/10 week strain and the buds look fine...let'her do her thing, if she's stressed always back down light pressure. Stress isnt always bad for cannabis either, and sometimes good, cannabis reponse to stressors can mean elevated terpene, oils, thc, etc. (advanced growers only). If your Pushing hard with Light/Respiration, then everthing else needs to be pushed.(VPD)