Please help me diagnose my plants

Hello,

This is my 2nd grow and I'm 2 weeks in since transplanting 2 different strains (Had a mix up with my seeds so I only know that one of them is either vanilla or critical kush and the other is a complete mystery, 1 is definitely looking like Indica and the other a sativa/hybrid)

Soil: I used a two of the best potting soils available (I live in a country which doesn't have any cannabis tailored products). One of the potting soils contains compost. I put the composted soil at the bottom and the gentler soil on top. Soil pH is 6.8

Set up: Indoors. 250 W HPS. Temp 26-28 C. Humidity 40-50%

In one of the plants (sativa/hybrid) I started noticing brown spots on the fan leaves that would eventually turn yellow and crispy and die. It mainly effected the fan leaves in the light doing the most work. The other indica plant was perfectly healthy.

After doing some research It looked like phosphorus deficiency. However, with the plant at such a young age I was skeptical that it was any kind of deficiency. Further reading suggested that I had over-watered it and that phosphorus deficiency appears with over-watering. This made sense as I may have given the plant too much water when I transferred it to the bigger pot. Although there were no signs of drooping at all, I decided not to water it until the soil dried off. At first it seemed like it was recovering but now it has spread even more. The soil is all dried up and I'm not sure what to do now.

The other indica plant is also starting to show the same signs. I'm beginning to think its a nute burn from the composted soil because the tips are also starting to yellow/brown. Can you get a nute burn from 100% natural organic composted soil?

I've attached some pictures for reference. First three are the sativa/hybrid which is suffering badly, and the other two are the Indica which is starting to get the same brown spots!

Any advice is much appreciated!
Thanks!
 
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Hi Max,
can you state the pH & ppm/EC of the water/feed you have given. (Name nutrients if any)
How are you gauging your ph? And ppm/EC?

One way of identifying excess/deficiency is Locating the affected area old/new (mobile/immobile nutrients) leave. The bellow chart gives you a rough idea.

The second demonstrates the narrow pH margins cannabis grows well in. Out side either wat can cause "nute lockout" .
Too tired today the scrutinize your pics but hope these help until someone else offers.
Happy growing.
PS & a good diagnostic flow chats
PPS. I've searched "diy soil" and keep coming across subcools super soil. It might help you find additives for your soil. I am adding a link to what I think is the recipe
 
Last edited:
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Hello,

This is my 2nd grow and I'm 2 weeks in since transplanting 2 different strains (Had a mix up with my seeds so I only know that one of them is either vanilla or critical kush and the other is a complete mystery, 1 is definitely looking like Indica and the other a sativa/hybrid)

Soil: I used a two of the best potting soils available (I live in a country which doesn't have any cannabis tailored products). One of the potting soils contains compost. I put the composted soil at the bottom and the gentler soil on top. Soil pH is 6.8

Set up: Indoors. 250 W HPS. Temp 26-28 C. Humidity 40-50%

In one of the plants (sativa/hybrid) I started noticing brown spots on the fan leaves that would eventually turn yellow and crispy and die. It mainly effected the fan leaves in the light doing the most work. The other indica plant was perfectly healthy.

After doing some research It looked like phosphorus deficiency. However, with the plant at such a young age I was skeptical that it was any kind of deficiency. Further reading suggested that I had over-watered it and that phosphorus deficiency appears with over-watering. This made sense as I may have given the plant too much water when I transferred it to the bigger pot. Although there were no signs of drooping at all, I decided not to water it until the soil dried off. At first it seemed like it was recovering but now it has spread even more. The soil is all dried up and I'm not sure what to do now.

The other indica plant is also starting to show the same signs. I'm beginning to think its a nute burn from the composted soil because the tips are also starting to yellow/brown. Can you get a nute burn from 100% natural organic composted soil?

I've attached some pictures for reference. First three are the sativa/hybrid which is suffering badly, and the other two are the Indica which is starting to get the same brown spots!

Any advice is much appreciated!
Thanks!
have you done a slurry test of the soil? if your sure the ph is 6.8 i wouldnt add lime because it will raise it to a neutral 7.0,all my grows both indoors and out i run 6.5 on my ph,even veggies,if your sure it is 6.8 add some gypsum to your soil by top dressing it,in those pots i would go for a 1/4 cup scrathed in,there is your phosphrus ,calcium nitride is your calcium with a touch of sulfur and magneese .i say before it to late do a slurry test and know your ph before you go anywere else. calcium nitride can be bought at any garden center even across the pond i would think,look for what ever helps blossom end rot in squash and tomato's that calcium nitride,use agriculture gypsum ,that can be bought any were,when you master this you will be able to take the soil from your own yard and grow,do the slurry test
 
Thanks for the replies everyone!

Ill do a slurry test and double check the pH. Any advice on how to calibrate your pH meter at home. I've seen some videos using baking soda and vinegar but those are far from the 6.5 range.

Didn't know agricultural gypsum existed! Thanks for the tip!
 
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313
Thanks for the replies everyone!

Ill do a slurry test and double check the pH. Any advice on how to calibrate your pH meter at home. I've seen some videos using baking soda and vinegar but those are far from the 6.5 range.

Didn't know agricultural gypsum existed! Thanks for the tip!
regular gypsum is for sheet rock and the putty for tape and bed,ag gypsum is difrent
 
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I run my soil at 7.0, typically. I have never had any problems with nutrient lock or anything else...I think the Ph is probably OK, where the problem might be is with overfeeding. 100% compost has a LOT of nitrogen in it, which can cause problems with water retention/drooping, and other materials, such as excessive P& K, can cause other nutrients to be unavailable, despite there being a ton of it in the soil.
To me, the plant looks seriously overfed. The glossy puffy leaves are one sign, and the funky deficiency pattern on the leaves are another. I base this on m experience and not by the charts or a book, although they are great references. The problem with the charts that are used to diagnose issues is that they all look about the same to all but the expert eye, and the issues can be a lot more complex than thought. If you overfeed one nutrient, other nutrients can be locked out or adversely affect the plant itself. While excessive P or K doesn't have much of an effect on the plants directly, they can interfere with the absorption of other nutrients. When you finally correct one problem, another pops up because of other treatments that were tried, or more nutes and cal-mag that were dumped on it. FWIW, Cal-Mag can cause deficiencies if used excessively... including magnesium deficiencies. Imagine a Calcium-Magnesium supplement causing magnesium deficiencies... how do you figure out that one?
I would flush the plants thoroughly, if they were mine. After flushing and resting for a day or two, I *might* give a snack, but there will still be a ton of stuff left from before...compost doesn't wash out it's nutrients too easily. Of course, this is just my opinion. Your mileage may vary considerably!
 
I run my soil at 7.0, typically. I have never had any problems with nutrient lock or anything else...I think the Ph is probably OK, where the problem might be is with overfeeding. 100% compost has a LOT of nitrogen in it, which can cause problems with water retention/drooping, and other materials, such as excessive P& K, can cause other nutrients to be unavailable, despite there being a ton of it in the soil.
To me, the plant looks seriously overfed. The glossy puffy leaves are one sign, and the funky deficiency pattern on the leaves are another. I base this on m experience and not by the charts or a book, although they are great references. The problem with the charts that are used to diagnose issues is that they all look about the same to all but the expert eye, and the issues can be a lot more complex than thought. If you overfeed one nutrient, other nutrients can be locked out or adversely affect the plant itself. While excessive P or K doesn't have much of an effect on the plants directly, they can interfere with the absorption of other nutrients. When you finally correct one problem, another pops up because of other treatments that were tried, or more nutes and cal-mag that were dumped on it. FWIW, Cal-Mag can cause deficiencies if used excessively... including magnesium deficiencies. Imagine a Calcium-Magnesium supplement causing magnesium deficiencies... how do you figure out that one?
I would flush the plants thoroughly, if they were mine. After flushing and resting for a day or two, I *might* give a snack, but there will still be a ton of stuff left from before...compost doesn't wash out it's nutrients too easily. Of course, this is just my opinion. Your mileage may vary considerably!
Thanks Jimster!
I watered my plants with a good amount of ph'd water and I think ill wait and see if it has any effect. If not ill definitely flush the soil and wait again. I don't want to add any nutrients any time soon because I know the soil has enough compost and the plant is still relatively young to show such an extreme deficiency, at least that's what I feel from my limited experience and hours of reading lol.
 
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Thanks Jimster!
I watered my plants with a good amount of ph'd water and I think ill wait and see if it has any effect. If not ill definitely flush the soil and wait again. I don't want to add any nutrients any time soon because I know the soil has enough compost and the plant is still relatively young to show such an extreme deficiency, at least that's what I feel from my limited experience and hours of reading lol.
Once your roots are developed, and your's probably are for the size of your plant VS the size of your pot, I would get on a regular watering schedule. Not like hovering over it with a measured eyedropper every three hours, but enough to keep the soil damp, but not wet. My guide was to take a handful of the growing medium about 6 hours after watering, and squeezing it. If more than a drop or two of water comes out, you are getting too much water retention. If you find that you plants are drying out too quickly, put a small catch basin under it to conserve any runoff water. My Sativa's often need this at the end of flowering. I saw the catch basin on your plants, so you shold be good. How big are your containers? It's hard to judge how big they are from the camera angle... at least to my old eyes. Keep us informed!
 
Once your roots are developed, and your's probably are for the size of your plant VS the size of your pot, I would get on a regular watering schedule. Not like hovering over it with a measured eyedropper every three hours, but enough to keep the soil damp, but not wet. My guide was to take a handful of the growing medium about 6 hours after watering, and squeezing it. If more than a drop or two of water comes out, you are getting too much water retention. If you find that you plants are drying out too quickly, put a small catch basin under it to conserve any runoff water. My Sativa's often need this at the end of flowering. I saw the catch basin on your plants, so you shold be good. How big are your containers? It's hard to judge how big they are from the camera angle... at least to my old eyes. Keep us informed!
Hi Jimster,
Hope all is well :)
So I’ve been watering my plants with pH'd water around 6.2. Although I can’t be sure because I haven’t been able to find calibration solution I’ve been using my past readings with my tap water as a gauge so I’m fairly confident its within range.

I also flushed the soil but I ended up with a lot of saprophytic fungus on the top layer of the soil. I think it was mainly because I had a lot of dead leaves there but I didn’t try flushing again. (used some cinnamon and baking soda)

I’m not sure if you can tell from the pictures but it looks like the plant got slightly better. The deficiency that was causing the brown spots seems to have gone but they’re still losing leaves at an alarming rate…especially the sativa.

Because the deficiency began at a young age I think it was either the pH or the composted soil that caused the issues. I didn’t want to give the plant any nutrients just in case the problem stemmed from the composted soil. The plants are now around 2 months old. Do you think I should try feeding them?

The sativa has lost most of its lower leaves, but the upper leaves have been yellowing as well. With the Indica its more random.

I wanted to start flowering soon but I don’t know if it’s a good idea in this condition.

Any advice is greatly appreciated! It hurts to seem them like this :cry:

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I also flushed the soil
it looks like the plant got slightly better. The deficiency ...
The plant looks like it's at that common stage for nutrient lockout (salt buildup). If that's what it was/is, the flush would have helped (as you say you noticed improvement.). This other member's observation fits lockout too:

It seems like they need some nutrients?
The next time you grow, monitor your runoff ppm. That helped me a lot when I had similar problems. I was ph probing the soil, and watching it become acidic. I was applying hydrated lime. I was a mess. But, after a couple grows I noticed the runoff ppm rose dramatically in transition or early-flower. When it reached 2500ppm, that's when I saw symptoms in the plant. I was feeding too much. It didn't appear during veg. The ppms seemed low (500ppm). But, at a very predictable time, it started going north. 1800ppm seems like a good place to be (for me). If it goes to 2000, I start cutting nute strength (and maybe increase volume of runoff). Now that I have my nute strength figured out, I rarely check the runoff ppm.

If that's the same thing you've had, you should see it happening (with the meter) before symptoms occur. It doesn't hurt to just meter it and keep an eye on trends. For me, that was the key to everything. (I don't even ph the nutrient solution anymore. I was doing that, chasing the soil ph dropping. But, adding "up/down" to the nutrient solution adds salts. So, I was ultimately making my too-strong problem worse. It's funny looking back on it. But, it wasn't funny then.).
 
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I'm still a little confused over this one. Some of the growth looks better, but some doesn't. The top looks very pale compared to a couple spots on the lower level. Is this just an effect from the camera or is it looking like this? How much water is your soil holding? Flushing only works when the soil doesn't get waterlogged and if the roots are struggling, all kinds of stuff can happen. Compost has a lot of nitrogen in it, which is good, but if it contains an unknown amount of P/K, or it's Ph is off a little, it could be at the root of the problem, since I can see no reason that you plants should be looking anemic. I could buy a bag of Promix (used in gardens worldwide, but mostly made out of Peat and perlite), put it in a 5 gallon bucket, water it fully and let it sit for a day, and plant a sprouted seed or a seedling/clone, and have a 4 ft plant in 5 or 6 weeks. Add a little 20-20-20 and you have a monster! I'm not saying this to be smart or abrasive, I just wanted to show that you shouldn't be struggling like this since it was doing well and then went south. Did you feed it any other nutrients at all? I know this is a lot of questions and a pain in the butt, but it helps to figure out what the problem might, or might not, be. Your problem seems like a deficiency, but deficiencies can be caused by actual deficiencies, or by causing nutrient lockout, such as too much Potassium interfering with the absorption of Phosphorus. Your plant sort of looks like it could use some cal-mag, but it too can compound issues if you have a high Ph, which calmag can raise as well. A foiliar application of it would be the best way to treat the plants without affecting the soil Ph.You can also do this with a lot of water soluble fertilizers, but a reduced concentration is used. Lastly is the baking soda and cinnamon. How much baking soda is used? If it is just a little that is sprayed on the soil surface it should be OK, but if it is soaking in, the sodium can affect the salinity of the dirt, and the bicarb can raise the Ph Adding the wrong thing could compound the problem, so the best thing to do is eliminate possible problems and see what is left. The fungus on top of the soil sounds like a water issue, Also, the 250W HPS is good for flowering, but you would do better with a MH bulb during vegetative growth, if you can find one to work with your ballast.
You did a nice job of getting your plant to the size it is, but something went wrong, either in the soil or something in the environment that we missed, like light distance or something that doesn't seem important. Sorry for the ramble.. been a long day!
 
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The plant looks like it's at that common stage for nutrient lockout (salt buildup). If that's what it was/is, the flush would have helped (as you say you noticed improvement.). This other member's observation fits lockout too:



The next time you grow, monitor your runoff ppm. That helped me a lot when I had similar problems. I was ph probing the soil, and watching it become acidic. I was applying hydrated lime. I was a mess. But, after a couple grows I noticed the runoff ppm rose dramatically in transition or early-flower. When it reached 2500ppm, that's when I saw symptoms in the plant. I was feeding too much. It didn't appear during veg. The ppms seemed low (500ppm). But, at a very predictable time, it started going north. 1800ppm seems like a good place to be (for me). If it goes to 2000, I start cutting nute strength (and maybe increase volume of runoff). Now that I have my nute strength figured out, I rarely check the runoff ppm.

If that's the same thing you've had, you should see it happening (with the meter) before symptoms occur. It doesn't hurt to just meter it and keep an eye on trends. For me, that was the key to everything. (I don't even ph the nutrient solution anymore. I was doing that, chasing the soil ph dropping. But, adding "up/down" to the nutrient solution adds salts. So, I was ultimately making my too-strong problem worse. It's funny looking back on it. But, it wasn't funny then.).
This sounds very similar and it just occurred to me about the compost. If it isn't too old, a lot of the nutrients might not have been available at the beginning, but after time and bacteria break stuff down more, more nutrients become available, raising your PPM. This is the only thing I can think of that would cause your nutrient level to rise, if indeed this is the case.
 
This sounds very similar and it just occurred to me about the compost. If it isn't too old, a lot of the nutrients might not have been available at the beginning, but after time and bacteria break stuff down more, more nutrients become available, raising your PPM. This is the only thing I can think of that would cause your nutrient level to rise, if indeed this is the case.
The plant looks like it's at that common stage for nutrient lockout (salt buildup). If that's what it was/is, the flush would have helped (as you say you noticed improvement.). This other member's observation fits lockout too:



The next time you grow, monitor your runoff ppm. That helped me a lot when I had similar problems. I was ph probing the soil, and watching it become acidic. I was applying hydrated lime. I was a mess. But, after a couple grows I noticed the runoff ppm rose dramatically in transition or early-flower. When it reached 2500ppm, that's when I saw symptoms in the plant. I was feeding too much. It didn't appear during veg. The ppms seemed low (500ppm). But, at a very predictable time, it started going north. 1800ppm seems like a good place to be (for me). If it goes to 2000, I start cutting nute strength (and maybe increase volume of runoff). Now that I have my nute strength figured out, I rarely check the runoff ppm.

If that's the same thing you've had, you should see it happening (with the meter) before symptoms occur. It doesn't hurt to just meter it and keep an eye on trends. For me, that was the key to everything. (I don't even ph the nutrient solution anymore. I was doing that, chasing the soil ph dropping. But, adding "up/down" to the nutrient solution adds salts. So, I was ultimately making my too-strong problem worse. It's funny looking back on it. But, it wasn't funny then.).
Hi again,

Thanks for all the help!

After reading your replies I decided to flush both plants again. My run off for both plants was around 2000 ppm so it seems like I definitely had a salt build up. I found a bit of water in the collector plate from my previous watering 2 days ago and the ppm of that was 4k ppm.

I didn’t think compost could be so harmful to a plant since it’s organic matter but I guess I learnt the hard way… as usual.

Now that I’ve flushed the plants what does this mean in terms of feeding?

Also I’ve read that molasses helps with salt build up. Is it a preventative solution or can I use it to actually break up the salt build up?
@az2000
But, it wasn't funny then.).
Lol! Thanks for the advice.
@Jimster
-Some of the growth looks better, but some doesn't. The top looks very pale compared to a couple spots on the lower level. Is this just an effect from the camera or is it looking like this?
Yes you’re correct the improvement/deficiencies are in random places.

-How much water is your soil holding?
Not sure how to measure this but when I came to flush them, it took about 1.5-2 litres before there was any runoff. My pots are around ~ 30x30 cm (13”x12”).

-I'm not saying this to be smart or abrasive, I just wanted to show that you shouldn't be struggling like this since it was doing well and then went south. Did you feed it any other nutrients at all?
No abrasion felt lol My first grow went much smoother than this (apart from a split main stem from LST :cry: ) and I thought I was going to do a better job second time round but I think the compost messed things up. And no I haven’t given it any nutrients at all.

-How much baking soda is used?
Very little since I was worried of its effects on soil ph. Mainly used cinnamon powder!

-Also, the 250W HPS is good for flowering, but you would do better with a MH bulb during vegetative growth, if you can find one to work with your ballast
In my last grow I switched from MH in veg to HPS in flowering. Both 250W. For some reason when I came to set up the MH again it's ballast was buzzing quite loudly and it’s in my room so I couldn’t stand the noise. Decided to just stick to an HPS this time and ill figure it out for the next grow. (For clarification, I dont have a digital ballast, each bulb has its own specific one)
 

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