Strange Yellowing (picture included) What is it??

The other day only one of them had this; what seems like a nutrient problem. Then today the three plants that were all closest to that one had this same problem, while the rest of the plants remained fine. It seems like it might be spreading from plant to plant. The leaves are being pruned off and discarded in case it is something very bad.

The soil was to be flushed today to see if it would help, but now that it looks like it could be a disease there will be no flushing until this problem is solved.

Please try to diagnose this plant. If you need more information or pictures I can post whatever you need.

Update; while the affected leaves were being trimmed it was noticed that a small drop of shiny white substance about 3-4 millimeters in width that appeared to be similar in pattern to these yellow spots was found on one of the leaves.

There is not a picture of it, but it looked like a tiny puddle of glue had been spread on the leaf and had been evaporating/leeching into the leaf. On the same plant there was what looked like a big gnat.

The gnats have been a problem in the past, but most of them seemed to disappear with a cinnamon dusting of the soil.

The plants have low drainage, and thus have not been getting a full gallon of water every 2-3 days, more like a couple cups every 2 days.

They are in 5-gallon buckets with organic soil, 12/12 light-cycle about a week ago with HID light about 3 feet (maybe a little less) from the plant, just switched to 3-12-6 Dyna-Gro "BLOOM" liquid nutrient with only two feedings so far (a little less than recommended dose) with one watering without nutrient since 12/12 started.

Today a lot of the lower level growth, especially suckers and fan leaves were (and most leaves affected by discoloration) were removed.

Is it safe to keep the affected plants in the room?

not gunna say for certain...but how is your PH? looks like a Ca. deficiency to me...maybe better pics would help, like of the whole plant.

gobskiii said:

not gunna say for certain...but how is your PH? looks like a Ca. deficiency to me...maybe better pics would help, like of the whole plant.

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The PH of the water is 7.5; the soil has not been tested. Sorry the plants were trimmed before a picture was able to be taken of that whole plant in particular, but here are a few pictures;


Another strange yellow spot.


Some of the new growth on one of the plants.


The whole room.

Thanks for helping! Any suggestions at all on how to better this grow would be appreciated.

Update: Another thing, the Humidity level is constantly around 80% and I don't have a dehumidifier. I've read that these wide fan leaves are likely so wide because the humidity level is so high and that this will decrease the quality of the buds. Is there anything that can be done to lower humidity without a dehumidifier?

Edit: After doing some reading about pH levels I've decided it is best to attempt to lower the pH of the water being given to the plants to about 6-6.5; I will check back in a few days with updated pictures of plants after a couple lower pH waterings. I will be using Vinegar unless I can find some pH down phosphoric acid or something.

i would just go and spend the little money you have to for some PH down...i have never heard of wide fan leaves due to humidity, and it effecting the quality of bud...wider fan leaves is indicative of indica dom. plants...normal. plants look a bit droopy, either over or under watering. but ya lower that PH, and you should be fine...also figure out if you are overwatering, or not giving them enough...and they will perk right back up.

as far as humidity goes...not sure how to lower it without a dehumidifier, but to avoid mold down the road just put a small fan in there 24/7

drop your ph of the water down to 6.3, 7.5 is way too high anything above 6.8 usually isnt good for your soil. the problem looks like your plants could be over watered, and from your pictures, the leafs are curling downward with yellow veins and yellow spots. could be over watering. SLOWLY water your plants til 10-15% is run off. and yes you need a small fan in there for some type of air circulation/ventilation.

Thanks for the input. There is a fan/ventilator and a box fan angled downward towards the plants to keep them from molding up.

As for the watering; they have only been getting a few cups every couple days because there is no drainage amendment in the soil; don't want to flood the roots. This leads me to believe that it's not over watering, but perhaps under watering. There is never run-off when they are watered.

About how much water does a 5-gallon bucket need? I have read that it's about 1 gallon of water, but it's difficult to get that many gallons to the grow site. I suppose it can be done if it must.

As for the pH problem, I have done a few tests and found that the filtered water out of the kitchen sink has a pH of lower than 6.8; exactly how low I cannot tell because the strip only shows results between 6.8-7.8 The water that is 7.8 was easily brought down with some lemon juice added.

I will increase the amount of water I give my plants. I think that under-watering along with the high pH level are the problems here.

Thanks again for the help.

If there is no run off in watering I think nutes could build up more quickly and cause burn . I'd be careful with that . But a lot of it looks pretty good , nice pics .

zuccotti said:

Thanks for the input. There is a fan/ventilator and a box fan angled downward towards the plants to keep them from molding up.

As for the watering; they have only been getting a few cups every couple days because there is no drainage amendment in the soil; don't want to flood the roots. This leads me to believe that it's not over watering, but perhaps under watering. There is never run-off when they are watered.

About how much water does a 5-gallon bucket need? I have read that it's about 1 gallon of water, but it's difficult to get that many gallons to the grow site. I suppose it can be done if it must.

As for the pH problem, I have done a few tests and found that the filtered water out of the kitchen sink has a pH of lower than 6.8; exactly how low I cannot tell because the strip only shows results between 6.8-7.8 The water that is 7.8 was easily brought down with some lemon juice added.

I will increase the amount of water I give my plants. I think that under-watering along with the high pH level are the problems here.

Thanks again for the help.

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Do not increase that water! You will kill them for sure, if you are using pots with no drainage then they ARE overwatered, and when coupled with the fact that your humidity is high you will continue to see this problem, another reason for drainage is so the roots get air, which your plants can not...they are drowning...they droop like that so any extra water can run off the leaves, underwatered plants leaves will curl up on the edges...because they are trying to hold the extra water in...

You can read all over this site how important drainage is and I see very little perlite in that soil...If you don't wanna drill some drainage holes in the bottoms of the buckets then you need to put a layer of small rocks, hydroton, perlite, or vermiculite in the bottom so the roots can get some air

missnu said:

Do not increase that water! You will kill them for sure, if you are using pots with no drainage then they ARE overwatered, and when coupled with the fact that your humidity is high you will continue to see this problem, another reason for drainage is so the roots get air, which your plants can not...they are drowning...they droop like that so any extra water can run off the leaves, underwatered plants leaves will curl up on the edges...because they are trying to hold the extra water in...

You can read all over this site how important drainage is and I see very little perlite in that soil...If you don't wanna drill some drainage holes in the bottoms of the buckets then you need to put a layer of small rocks, hydroton, perlite, or vermiculite in the bottom so the roots can get some air

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There is no perlite in the pots at all, but there ARE drainage holes at the bottom of them. Some sand was added to the organic soil mixture to get some increased drainage, but besides that the drainage is probably low.

I can't see how these plants are being over watered on whatthey've been getting; about two cups of water or less per plant every 2-3 days.

I'll update a little later after the plants have been checked on.

I think I need to increase the water for these guys, but missnu has me scared saying I'll kill them if I increase water.

Here are today's photos:


I checked a few of the pots and they were all in the red for moisture levels; I don't think they're over watered.


Here is a close up a leaf that seems to be wrinkling up on the edges.


Damage on the leaves.


Another shot of some leaf damage.


This one is definitely not as green as it should be.

Alright. So I'm pretty sure I'm going to increase the water levels, I do not think the roots are suffocating because the moisture level seems to be pretty low. Temperature today was around 60 degrees. It's getting cold out. Any ideas on how to warm up my room without buying a heater?

I am still a little scared by the thought of over watering these guys to death, but I am almost positive they need water, so I sprayed some seltzer water on the leaves today because I have read that the added co2 really helps growth and I wanted to avoid putting water directly into the soil so I wont suffocate the roots in case missnu is right. The moisture levels in the soil are reading the lowest they have been during the entire grow, so I need more opinions on what to do since I am almost positive that over watering is not the problem, but the only advice I've been given is that I'm over watering.

If I don't get any replies I'm just going to increase watering.

When growing in soil no matter what pH you adjust your nutrients too it will buffer to the mediums pH within a half hour. pH up and down added to your water will buffer the waters pH. But it will do nothing to adjust your mediums pH. Lockup and lockout of nutrients is actually pretty rare when growing in soil. Most of the time is just simply underfed or being fed an unbalanced diet...

lower ph or rather test the soil ph to see where it stands first
water them...FYI,plants show similar symptoms when over/under watered
put a desiccant in the room for the humidity problem
after you do these things,step back and see what you have then

Listen to watchhowidoit. He's the one voice of reason here. Forget what the pH of the solution going into the soil is, 'cuz the soil is gonna change that to whatever the pH of the soil is. You have to know the actual pH of your soil. Run-off is no indicator either, as it hasn't been in contact with the soil long enough to change. Soil pH is extremely stable. Lock out is a very rare thing. There is a tutorial on how to check the soil pH in my journal.
Looking at some of the pics, I'd say you have some abrasion going on from the leaves rubbing each other when swaying in the fan breeze. Not saying thats all of it, but it's some or most of it for sure.
When watering, always water until you get run-off, then let them dry out before watering again. You can water them, lift the pot to feel the weight. Then let them dry out, again check the pot weight. That will tell you when to water.
As for the humidity, if you can extract that moisture laden air and vent it out of the room, that will go a long way to lowering the RH. If you vent it to the outside, you'll need to get some odor control going on with a carbon filter. You can't beat a good dehumidifier.
I cant advise you on the nute thing, 'cuz I know nothing about those nutes. Next grow, you might consider going organic. Keep this as simple as it really is. Far too often, newbs make this a whole lot more complicated than it has to be. This is basic biology and basic botany. MJ is a plant, nothing more. Not every little quirk or spot is a life shattering problem.
Your fans are large because that's what's encoded in the plants genetics, not because of the humidity or other environmental factors. Quit pulling off the fans, that's what will affect your bud sizes more. They are the energy producers for the plant. When the plant no longer needs them, it will shed them. If they block light to a bud site down the road, tie it off somewhere out of the way, but don't cut the thing off!!
All things considered, they look pretty good to me. A bit on the dry side, but all in all pretty damn good.

Alright. Thanks for the input. Good to know they look alright to you; my last grow (first ever) was outside and I didn't have to worry about any of these problems, my plants were healthy and strong from start to finish. I don't mean to freak out about the tiny scratches and discolorations, I just want to make sure it's nothing too serious. Before I got my fan in there, there was some fungus or mold growing on the soil and gnats in the room, got rid of that by dusting with cinnamon and installing the fan, but I'm being extra careful because I hear a mold or fungus problem can ruin an entire crop, and I have a lot of time invested in this.

I'll follow your guide on testing my pH, would you suggest that I remix my soil with some perlite (and pH correcter if necessary) and transplant these guys? (they're about a week into 12/12 cycle still haven't shown sex yet, I changed the light cycle when they were 25 days into veg) or should I wait it out? For my next grow I'm thinking of doing a deep water culture; I like organic a lot, but I want to try out hydro and see which method I prefer. I think I'll prefer organic but we'll see.

Thanks again for all the help guys, I really appreciate it

Edit: Oh, and thanks for the heads up about not removing fan leaves, I only removed the fans from the lower 1/3rd of the plants, I read somewhere that this helps create air circulation and prevents mold.

Right now there is 1 plant per square foot, with 2 of the pots holding 2 plants ea. that I had started late. I figure that once they show sex and I get the males out of there, there will be about 2 square feet for each plant; would it be practical to top/fimm them at this point in order to get two main colas, or should I continue letting their apex cola remain dominant? Not trying to over-complicate things, I am just curious and I really enjoy learning about all of this. Thanks

Don't do anything until you know the pH.

Also,those last pics you posted looks like a Mg def
Sorry I didn't read thru the whole thing before posting last time

If it is, it's not anything to worry about. Just feed some cal/mag periodically to cure that. But cal/mag deficiencies in cannabis will typically show up early to mid flower in soil. I doubt that its a deficiency.