I'm so lost, plants are sick

[Fourpey]

Ok so this is my first grow and my plants are sick looking, looks like magnesium deficiency. They've been fighting this for the past week and a half since it appeared. At first I was following H3ad's formula of 6ml micro, 9ml bloom and 5ml of calmag per gallon of tap water (500ish ppm added up). Shit went down and now they look like this. It was said to me that it might be lockout from a pH swing which would've caused the mg def. I have been pH'ing my feed to 5.8 religiously and monitoring the ppm and pH of runoff which was coming out always around 200 more than input (700ish) and 6.2 pH. After a while seeing my plants fail to get better I ditched the 6/9/5 feeds, flushed with 1 gallon per plant of 5.8 pH distilled water. I then decided to follow the GH dosage chart on the bottles. I went for the early veg strength (800ppm) since this is their 4th week from germinating. I also started yesterday feeding twice a day 900ml per feed (I around 40% runoff) in case salt buildup might have been the reason for the plants sickness. The runoff is still coming out at 6.2, the ppm now is coming out lower (500ppm) than what I put in which I assume is good because the plants are eating and no salt buildup. But am I underfeeding? The new growth is bright green as it should but all the big fan leaves have yellow spots, interveinal yellowing, some are crisping up, the tips of the leaves curl down (seems worse right after feeding). I don't know what to do...

I know there are many other factors at play so here is how I set up the environment:

2x3x6 tent
I have 2 100w LED panels at 50% and 18 inches from top of plants
Daytime temp is 72-75f / Night temp 66
Fan is on lvl 1 not blowing directly on plants
RH 60%
VPD is always between 0.8 and 1.2
3 gallon coco perlite (70/30) fabric bags
2 feeds of around 900 ml / day / per plant
exhaust running 24/7 at 20%
bottom intake flaps half opened
Baseline ppm of my tap water is 162

I know that the leaves that are damaged won't go back to normal. But what would be the signs of the plant healing?
Is the fact that its still has healthy green new growth a good sign or will that go to shit soon?
I have so many questions sorry for my noobness. I'm trying real hard to understand though. I think I didnt rinse enough the coco to start with and have read a few weeks too late that buffering coco is a thing. I need to mix another batch of feed today and I don't know what to do anymore. Calmag, no calmag. Higher strength or lower. If I'm getting around 40% runoff should I really be watering twice a day?

Please help! Thanks in advance

 

[Imzzaudae]

Hello and welcome to the farm.
Sorry your plant has you so stressed bud. But your going to be all fixed up real quick.

Your plant is suffering from light stress.
Set your lights at 65% 24 to 30 inches above the canopy.

The big white blotch is light burn. You can take the leaf off.
All of the leaves that look like someone wiped the green off are very light stressed but will be ok after you adjust the light level.

Your plant colour is pretty good and she will darken up a bit when light levels are sorted. You can give her a little extra potassium and phosphorus buy watering with a flowering mix fertilizer a few times. Try feeding her a flowering mix next 2 feedings to get levels up in the pot, then once a month instead of a veg mix fertilizer. This will green up the purple stems for you.

If you have any questions pm me and I will delve a little deeper into what I think is up, but I think your plant is going to be just fine.

Adjust lights.
Give her a little higher level potassium and phosphorous fertilizer.
Something with a low first number / Nitrogen and high middle / Phosphorus and last potassium, NPK numbers.
2 feedings then once a month as needed.

Pick a P.H number you want for watering. Mix your fertilizer solution and adjust the PH as close as you can.
Within a point or 2. Even just plane water should be P.H adjusted.
Don't chase. Just stick with 6.5 6.7 what ever you decide.

 

[Fourpey]

Hello and welcome to the farm.
Sorry your plant has you so stressed bud. But your going to be all fixed up real quick.

Your plant is suffering from light stress.
Set your lights at 65% 24 to 30 inches above the canopy.

The big white blotch is light burn. You can take the leaf off.
All of the leaves that look like someone wiped the green off are very light stressed but will be ok after you adjust the light level.

Your plant colour is pretty good and she will darken up a bit when light levels are sorted. You can give her a little extra potassium and phosphorus buy watering with a flowering mix fertilizer a few times. Try feeding her a flowering mix next 2 feedings to get levels up in the pot, then once a month instead of a veg mix fertilizer. This will green up the purple stems for you.

If you have any questions pm me and I will delve a little deeper into what I think is up, but I think your plant is going to be just fine.

Adjust lights.
Give her a little higher level potassium and phosphorous fertilizer.
Something with a low first number / Nitrogen and high middle / Phosphorus and last potassium, NPK numbers.
2 feedings then once a month as needed.

Pick a P.H number you want for watering. Mix your fertilizer solution and adjust the PH as close as you can.
Within a point or 2. Even just plane water should be P.H adjusted.
Don't chase. Just stick with 6.5 6.7 what ever you decide.

Hi! Thanks for your input

What makes you say that its light stress? I'm curious as to what signs tell you that. I used the photone app for what its worth and it says around 300ppfd. I've been reading alot online and everything is pointing at a magnesium and or calcium deficiency. The big yellow spot on the leaf is from a drop when I watered. Some leaves are crisping up, and tips are curling down though and I agree with you it might look like light stress for these symptoms.
Also I'm growing in coco so I always water with nutrients, I'm using the GH Flora series trio and CalMag.

 

[ArtfulCodger]

Another vote here for light stress. It's not an either-or thing...light stress or deficiency. It's a balance. You get yellowing between the veins when the roots can't keep up with the demand from the light level, for any of a variety of reasons.

 

[Fourpey]

Another vote here for light stress. It's not an either-or thing...light stress or deficiency. It's a balance. You get yellowing between the veins when the roots can't keep up with the demand from the light level, for any of a variety of reasons.

Ok! I went ahead and put my lights at 24 inches and left them at 50%. Photone is now reading 250ppfd at the top of each plant. Its weird because its so low. If I would follow the AC Infinity recommendations for my lights, they would be at 18 inches and 80% intensity...

I have 2 100w full spectrum LED panels in a 2x3x6 tent. Is it too much? Is that why they get light stressed?

Its an indica GDP if that helps pinpoint why they need so little light.

 

[ArtfulCodger]

You have 200W hanging over six square feet of tent space...so a little more than 30W of LED per square foot. That's about right for finishing power, for a grow in soil with ambient CO2. It's too much early on. A light meter can tell you how much light you have, but it can't tell you how much light you need. There are too many variables it doesn't know anything about. Luckily, your plants will tell you everything you need to know about the light level. When the leaves are flat, level, and vibrant green, they're happy with the light. When they're any other shape or you see any other color (except during the fade, of course), they're not.

 

[Fourpey]

You have 200W hanging over six square feet of tent space...so a little more than 30W of LED per square foot. That's about right for finishing power, for a grow in soil with ambient CO2. It's too much early on. A light meter can tell you how much light you have, but it can't tell you how much light you need. There are too many variables it doesn't know anything about. Luckily, your plants will tell you everything you need to know about the light level. When the leaves are flat, level, and vibrant green, they're happy with the light. When they're any other shape or you see any other color (except during the fade, of course), they're not.

What do you mean by finishing power? For flowering? And do you mean if the lights would be at 100% intensity? If my two lights are at 50% intensity is that still too much for veg? Sorry for all the questions I'm just trying to figure this out.

Its just that from everything I've read (which I now realise I was missing info) People seemed to just set the intensity of the light low from seedling and crank the intensity as the plant moves to veg and then flower. Following a ppfd chart and measuring with photone. Keeping the light at 12 or 18 inches depending what the plants demand.

I did not take account of the fact I have 2 lights in a small space, I did'nt know it would mean I needed to use them at lower intensities.

 

[Thatoneguyyouknow_]

you can give a plant 500-700 pfd and its not going to give cannabis light burn. Especially if its already been at that intensity for a bit. You can wean a plant into light in excess of 1000pfd and itll be fine, especially if its not sweltering hot.

I have a couple seedlings under a 100w panel at 100% 12" away right now. And theyre fine. Th seedlings i transferred outside a month or so ago, that arre now big-ass bushses, i had about 6" from that panel at 100% within their first week of life because i was planning on moving them outside, they were 3-4" off by the time i made the full transition. Outside, where the pfd can be in excess of 2000 and heat can rise above 90F. They transitioned just fine with no signs of stress whatsoever, in fact they exploded in growth immediately.

People grow this plant in full sun in southern california lol.


Ive never had a seed grown plant out grow its root system unless it was allowed to bind up before transplanting.


And in pure coco, i definitely wouldnt run at 6.5-6.8 like was mentioned. Your medium is completely inert, you do need to be hovering more toward a hydro PH range ime. But expanded coco bricks make better reptile bedding and mushroom substrate casings then soiless medium for a rapidly growing plant but thats just imo.

 

[Fourpey]

you can give a plant 500-700 pfd and its not going to give cannabis light burn. Especially if its already been at that intensity for a bit. You can wean a plant into light in excess of 1000pfd and itll be fine, especially if its not sweltering hot.

I have a couple seedlings under a 100w panel at 100% 12" away right now. And theyre fine. Th seedlings i transferred outside a month or so ago, that arre now big-ass bushses, i had about 6" from that panel at 100% within their first week of life because i was planning on moving them outside, where the pfd can be in excess of 2000 and heat can rise above 90F. They transitioned just fine with no signs of stress whatsoever, in fact they exploded in growth immediately.

People grow this plant in full sun in southern california lol.


Ive never had a seed grown plant out grow its root system unless it was allowed to bind up before transplanting.

I know and thats what I've read. My plants are getting 300 ppfd atm and people are telling me its light stress. I don't understand...

 

[Thatoneguyyouknow_]

I know and thats what I've read. My plants are getting 300 ppfd atm and people are telling me its light stress. I don't understand...

they are incorrect lol. I can make that statement with total confidence.

 

[Fourpey]

they are incorrect lol. I can make that statement with total confidence.

whew... Well if not light stress, what do you think is the problem? what can I do

 

[HerbalEdu]

- few burn can sometime happen locally on few leaves without any perticular reasons:

exemple the plants, and two blades of one leaf on one pheno

- i have had numerous time some phenotypes showing leaves like yours, with slight interveinal discoloration, it never got any worse than that.

 

[Fourpey]

- few burn can sometime happen locally on few leaves without any perticular reasons:

exemple the plants, and two blades of one leaf on one pheno
View attachment 2192438View attachment 2192439

- i have had numerous time some phenotypes showing leaves like yours, with slight interveinal discoloration, it never got any worse than that.

Yeah but my plants look much worse. They have purple petioles, tips curling down, interveinal yellowing, some edges have slight burn, orange specks here and there, some parts of top leaves are crisping a bit, and bottom fans are dry and getting crispy af.

 

[Imzzaudae]

Start looking on line for symptoms of light stress. I know from years of study and experience growing that the markings on your leaves are caused buy very intense light. The same goes for the white blotch. This kind of burn. I have seen it 10,000 times helping guys just like you over the last 3 years in the forum. Do yourself a favour. Get rid of the light meter and start studying. Learn how to look at a plant and see light stress and light burn as well as deficiencies. This will come in time if you put in a little effort studying.

It won't be long and you will just see the leaves rolled up or tips rolled up or down and have a general understanding as to why.

Do yourself a favour.
Move the light up 30 inches and adjust the output as described for now and let the plant recover.
Remove the leaf with the burn. Give her some time to grow.

Study! Learn how to read your plant rather than playing with junk light meters.

 

[HerbalEdu]

i m not seeing anything too dramatic from the photos you've shared.

aside may be some lower stages are missing, trimmed or decayed over time ?

 

[Fourpey]

Start looking on line for symptoms of light stress. I know from years of study and experience growing that the markings on your leaves are caused buy very intense light. The same goes for the white blotch. This kind of burn. I have seen it 10,000 times helping guys just like you over the last 3 years in the forum. Do yourself a favour. Get rid of the light meter and start studying. Learn how to look at a plant and see light stress and light burn as well as deficiencies. This will come in time if you put in a little effort studying.

It won't be long and you will just see the leaves rolled up or tips rolled up or down and have a general understanding as to why.

Do yourself a favour.
Move the light up 30 inches and adjust the output as described for now and let the plant recover.
Remove the leaf with the burn. Give her some time to grow.

Study! Learn how to read your plant rather than playing with junk light meters.

Yes I have moved the light up to 24 inches and reduced intensity to 40% instead of 50%. I'll see if that helps

 

[ArtfulCodger]

What do you mean by finishing power? For flowering? And do you mean if the lights would be at 100% intensity? If my two lights are at 50% intensity is that still too much for veg? Sorry for all the questions I'm just trying to figure this out.

Finishing power is light intensity at the end of flowering. I run LEDs at the top of my tents, and start veg at 25% power. By the end of flower, it's a lot higher. Anyone who tells you what your light intensity should be without seeing your garden is guessing. The plants will tell you what they want.

 

[Fourpey]

Finishing power is light intensity at the end of flowering. I run LEDs at the top of my tents, and start veg at 25% power. By the end of flower, it's a lot higher. Anyone who tells you what your light intensity should be without seeing your garden is guessing. The plants will tell you what they want.

Having them at the top would be pretty convenient, no more need for adjusting height, only the intensity? Do you suggest I do that and if so what intensity should I set them at?

 

[Fourpey]

i m not seeing anything too dramatic from the photos you've shared.

aside may be some lower stages are missing, trimmed or decayed over time ?

I topped my plant at the 4th node and removed the first and second set of fan leaves because they were getting worse and worse.

 

[ArtfulCodger]

Having them at the top would be pretty convenient, no more need for adjusting height, only the intensity? Do you suggest I do that and if so what intensity should I set them at?

It works great for me. What you do is up to you. After four weeks in my seedling area, I put my plants under 25% of my finishing wattage for 18 hours a day for the first three weeks of veg. I bump that to 50% of finishing on the first day of week four of veg. Change the timer to 12/12 when the plants are the size and shape I want. Then up to 75% on the first day of week three of flower, and finally to 100% of finishing power on the first day of week 6 of flower. That schedule stretches out with longer flowering cultivars. "100% of finishing power" isn't necessarily 100% on the dimmer. Depends on how much light you have, how much space, what you're growing, how you're growing it, and how well. For me, the plants' response rules. When the leaves are flat, level, and green, they're happy with the light. When they're contorted in any way, or showing any other color, I turn the light down. When they're healthy and still praying at the end of the day, I turn up.