Leaf Issues

[DevilDog_0651]

Good Morning! I have some leaf discoloration, and am having a hard time differentiating between what the issue could be. Below are the details

Strain: Power Plant (Photoperiod) by Growers Choice (Sativa dominant landrace from South Africa - whatever that means)
Age: Started end of January, flipped to 12/12 two and a half weeks ago (on the 13th)
Medium: Fox Farms Coco Loco (treated like soil, feed pH to be in range of 6.3 to 6.8)
Pot: 20 gallon fabric pot
Nutrients: Bloom nutrient, Smart Tea, Silica product, Cal+Mag (I feed all of this every watering which is normally every 4 or 5 days or so)

Known Issues: I believe I have some Nitrogen toxicity, how should I address this? Just do water for a cycle then feed half strength? What I don't know about is the rust / brown color on the fan leaf edges. Please help, everything was going so well until I switched to flower and started the bloom nutrients.

 

[namvet25]

Don't worry about a few leaves browning on a plant that old,just keep using bloom nutes and cal/mag.You might want to thin her out and get rid of a few spindly branches and keep the larger ones.

 

[DevilDog_0651]

okay, I cleaned up some lower growth two days ago, do I need to wait a few weeks before pruning again since she is flowering? A lot of leaves are affected, so that's why I was worried. Since I need to thin her out, should I start by just removing the leaves which are discolored?

 

[DevilDog_0651]

@namvet25 - should I wait a week or so to thin her out? Just don't want to stunt her while she is in flower.

 

[namvet25]

Wait until flowers develop then remove any lower spindly branches that look like they won't get enough lite.

 

[Waira]

Looks like K defc., or k toxicity-- ironically they show pretty much the same: burn at the 'teeth" tips along margin..... running coco like soil is going to bite back, and that may the case here with possible nute salt build-up in the coco,.... How much run-off you generating each time? This is what purges out the excess, and resets the table with a balanced nute solution... typically this is 20+%
if you've never done this, never checked the TDS/EC, or pH, then you have some work to do mate! No fix can be had by being clueless about what's up in that pot.... coco is a specialized medium, soilless by definition, and has a lot of do's and don't's associated with it...
With no info, i can only guess at what's wrong, and can't offer safe help/advise because of that,... time to do a run-off test! Use only RO/Di water, very low ppm's is critical to this; collect the first cup of run-off and take pH and TDS/EC readings, and p[ost them so the next step can be taken,...

 

[Mañ'O'Green]

Talk about an Orphaned Product. The information about growing in Coco Loco is almost non-existent. I don't agree with the underlying premise of using it like soil. It has minimal NPK starting numbers and with the dolomite lime in there you need a good soil PH probe because there is no other way to know what the PH in the root zone is. Salt build-up is almost guaranteed if you have not been fertigating to run-off?

Did I read that right they vegged for 4.5 months?

Off the top of my head PH problem looks like this as well as the other possible causes mentioned before.

This list of ingredients to make a medium for cannabis does not make sense to me. It is not soil or hydro?

 

[DevilDog_0651]

Looks like K defc., or k toxicity-- ironically they show pretty much the same: burn at the 'teeth" tips along margin..... running coco like soil is going to bite back, and that may the case here with possible nute salt build-up in the coco,.... How much run-off you generating each time? This is what purges out the excess, and resets the table with a balanced nute solution... typically this is 20+%
if you've never done this, never checked the TDS/EC, or pH, then you have some work to do mate! No fix can be had by being clueless about what's up in that pot.... coco is a specialized medium, soilless by definition, and has a lot of do's and don't's associated with it...
With no info, i can only guess at what's wrong, and can't offer safe help/advise because of that,... time to do a run-off test! Use only RO/Di water, very low ppm's is critical to this; collect the first cup of run-off and take pH and TDS/EC readings, and p[ost them so the next step can be taken,...

@Waira - okay, I will get runoff numbers next time I feed. Normally I feed her about 5 gallons of water, and plenty runs off, but not 20%. I check the pH, and the TDS of my feed solution, but not the runoff. So you're saying stop using my tap water? That has about 140ppm and pH is around 8. Can I used like spring water from bottled water? That PPM is way lower.

 

[DevilDog_0651]

Talk about an Orphaned Product. The information about growing in Coco Loco is almost non-existent. I don't agree with the underlying premise of using it like soil. It has minimal NPK starting numbers and with the dolomite lime in there you need a good soil PH probe because there is no other way to know what the PH in the root zone is. Salt build-up is almost guaranteed if you have not been fertigating to run-off?

Did I read that right they vegged for 4.5 months?

Off the top of my head PH problem looks like this as well as the other possible causes mentioned before.

This list of ingredients to make a medium for cannabis does not make sense to me. It is not soil or hydro?

Yes, that's correct, it has vegged for almost 5 months. I will probably try a different product next time because nobody ever seems to know much about Coco Loco...So should I flush? I am in week 3 or 4 of flower, is it too late?

 

[Mañ'O'Green]

Yes, that's correct, it has vegged for almost 5 months. I will probably try a different product next time because nobody ever seems to know much about Coco Loco...So should I flush? I am in week 3 or 4 of flower, is it too late?

If you are adding 5 gallons of water with little run-off you are letting your pots get too dry! What you need to learn about watering will come with practice. Here are the basic rules: Never let the soil dry out. Soil and or coco can become hydrophobic if allowed to dry. This means it repels water. This in turn will create dry pockets in the soil and roots there will die. If your soil - coco have accidentally dried out use a surfactant to help re-wet it. I like yucca powder. Don't let soil remain soggy by watering too much too often. Root rot, damping off, molds, fungus gnats and other problems start in soggy soil. When you do water water the entire pot. How to learn when to water starts before you plant the seed. Fill your container with fresh soil/coco and weigh it (heft it) this is the lightest weight and consider it a dry pot. Now slowly water until the soil/coco will no longer absorb the water and run-off begins; weigh the pot (heft it) this is the maximum water, the wettest the pot can get. The difference between wettest and driest is the maximum water weight, for ease of explanation lets just say the water weighs 20 pounds. When the pot loses 10 pounds (half of the water weight) it is time to water again. There is an art to watering.

No it is not too late to fix coco. It is one of the reasons we use it in cannabis. This is radical and I usually ony recommend it in a dire situation. I do not know if we are there but here is the procedure. Use distilled or RO water PH 6.2 to flush the pot twice it's volume or 200% run-off. The forest products in this are a wild card but this should rinse it well. Now run through 150 PPM of Cal-Mag and wait 30 minutes. Now fertigate with 70% strength balanced (that means ALL of the recommended products in the vendor line) bloom nutrients plus 50 PPM of Cal-Mag. Add Mykos or any other beneficial microbes, kelp, Humic Acid, B1 and a P-K booster all at 70% of the recommended strength. Fertigate all of these nutrients at the same time. Then from this point forward treat this like a hydro grow and fertigate balanced nutrients every time to 15% run-off.