pale leaves with dried brown spots

[slackerbri]

Hi everyone, I have a few girls who were recently transplanted and have started to go from a nice rich dark green to a pale green with some brown spots on the larger leaves which dry out and crumble off.

I dont have a ton of relevant info on hand as I am not home right now but these pics were taken today and although I wont be home until monday evening I can have some rudimentary tasks preformed by someone else.

Here is what info I can provide please ask any more diagnostic questions as you would like and hopefully I can resolve my issue.


SOIL:
What STRAIN are you growing? Schrom
What was the establishing technique? (seed or clone?) Clone
What is the age of your plants? Clones went under 125W CFL for 2 weeks and then under 400w mh w/ Hortilux Blue bulb
What PHASE (seedling, vegetative or flower) are the plants in? Veg
What Technique are you using? (SOG, SCROG etc) Just a clone is soil
What size pots are you using? (Include how many subjects to pot) 12" subterra-res system aprox 4gal of soil space
What substrate/medium are you using? (percentage of perlite, vermiculite...etc?) 50/50 BioCanna Soil/Canna Coco
What Nutrient's are you using?How much of each? How Often? *Knowing the brand is very helpful* Bio Canna Bio Vega mixed as directed once a week in res, Canna Rhizotonic Once a week over the soil and once fed Bio Vega over the soil
What is the TDS/EC/PPM of your nutrients used? Dont know
What is the pH of the "RUN-OFF"? Dont know
How often are you watering? Fed aprox twice a week once in res and once over soil with rhizotonic
When was your last feeding and how often are you feeding? Fed weekly
What size bulb are you using? 400w hortilux blue mh
What is the distance to the canopy? 30cm
What is your RH Factor? (Relative Humidity) aprox 50%
What is the canopy temperature? mid 70-deg F to low 80's at hottest
What is the Day/Night Temp? (Include fluctuation range) no less then 68 deg no more then 82 deg
What is the current Air Flow? (cfm etc.) aprox 200cfm
Is the fan blowing directly at plants? No
Is the grow substrate constantly wet or moist? Damp in center of bucket drier towards edges
Has plant been recently pruned, cloned or pinched? Transplanted 10 days ago
Have any pest chemicals been used? If so what and when? Green Light Fruit and Tree spray as a preventative measure as I once had mites but I've used this on a few crops with no issues
Are plant's infected with pest's? dont think so



Well any help is greatly appreciated, attached are pics from today.

 

[MynameStitch]

Well for one you really need to know the run off of your plants it's important. Another thing, since you are using a 50/50 mixture of soil and soiless medium you may run into pH issues... because both of those need different pH levels; so you may have to find a medium if you find problems you can't fix.

Another thing; how much are you feeding them? rhizotonic is not a fert, it's a suppliment to enhance root growth in seedlings and cuttings.
You need to get them some different kind of nutrient and stop using the rhizotonic; they have a well established root system now and do not need it anymore.

You have access to a hydro shop? I would feed every 5 to 7 days since you are in a 50/50 mixture; coco needs to be watered and fed more than soil; but you are in a mixture.

THey look like nitrogen issues; they also look like they have moisture stress, how often are you watering them?

In the first picture what is that black tube sticking up out of the soil?

 

[slackerbri]

Stitch,


I was advised to try this mixture of coco and soil by someone locally who said they had good results. When I get home in a few days I can chek the runoff and see whats up.

I hear ya about the Rhizo, I wasnt using it as a fert but like you said as a supplement to enhance root growth from the transplant to relieve stress. I usally fill the resovoir(black tube in pic) once a week and I am good but I was also told that with this coco mixture it was advisable to top feed some nutes into the soil mixture.

The medium does seem to retain mositure a bit more then soil itself would, could that be part of the problem? Could the roots be somewhat suffocated causing the plant to not take up nutes correctly? Usally I just run soil and only feed subterrainaly but like I said I was advised with coco to do a bit more in the way of feeding over top of the medium.

Thanks for the input, before I left tuesday I fed them nutrients over the top of the medium and filled the res in hopes they would improve. Also those pics were taken yesterday, not today as I previously mentioned so possibly there was some change since then, I'll have more pics in a lil while.

Well for one you really need to know the run off of your plants it's important. Another thing, since you are using a 50/50 mixture of soil and soiless medium you may run into pH issues... because both of those need different pH levels; so you may have to find a medium if you find problems you can't fix.

Another thing; how much are you feeding them? rhizotonic is not a fert, it's a suppliment to enhance root growth in seedlings and cuttings.
You need to get them some different kind of nutrient and stop using the rhizotonic; they have a well established root system now and do not need it anymore.

You have access to a hydro shop? I would feed every 5 to 7 days since you are in a 50/50 mixture; coco needs to be watered and fed more than soil; but you are in a mixture.

THey look like nitrogen issues; they also look like they have moisture stress, how often are you watering them?

In the first picture what is that black tube sticking up out of the soil?

 

[MynameStitch]

See, I have never seen someone do a setup like yours; this is most defiantly a first... a res with soil is something I thought I would never hear off.....

Did the person who recommended this to you grow cannabis in it? If not.... then it's a whole different story.

So how is this setup, I do not understand this too well... there is a res underneath your soil? Or pot?

Yes, when the soil stays wet it causes nutrients to be poorly absorbed; and wet soggy soil causes nitrogen to become locked out very easily.

I think it's a combination of having to wet soil and not feeding is your issue; but again I never seen someone use a setup you have...... where did you go about working with this setup and why?

It's like hydro and soil in one.... can't work both ways.

 

[slackerbri]

Stitch,


I've been growing with these for about a year or so now and when I used straight soil or a soil/perlite mixture it works great. I would only water over the top of them once and after that I would only fill the res which is built into the bottom of the bucket, the top soil would stay bone dry and solid and the roots would just absorb the nutes via cappilary action from the res. The company that makes them is based in socal and they are super simple to setup.

I thought it was a bit kooky at first but then tried it and it gave me way better results then just a standard bucket when I did the same strain(C-99) side by side, I saw someone else who ran a system very similar to the one I used and called it "Terraponics".

I've always used the same BioCanna nutes with this system and it worked great but you did mention the downside of the soil being damp and I think that may very well be a major part of the issue at hand, any simple suggestions?

Thanks again, much appreciated

 

[MynameStitch]

Really can't give you much advice, cause I do not know much about it other than I can see loads of trouble the way the system is designed, what works for you may not work for others; but I am glad it works out for you...... but it's hungry for nitrogen, mostly cause for soggy soil...... and no feeding.... first let the soil dry out and then feed them......

 

[slackerbri]

Sounds like a plan, I'll keep you posted.

Here is a pic of an old crop that used the same buckets, I only watered the soil once when the clone was originally planted otherwise these were completely 100% bottom fed.

and here is another if you look along the right side you will see some newer clones that were just put in soil and the larger ones were in soil aprox 2 weeks.

let me know if anyone has any questions and thanks again Stitch for your input.

 

[Kr@kEn]

You need perlite added to your medium. Half perlite would work great. There's nothing wrong with mixing coco with soil but you need drainage and air to your roots which seems to be lacking. Perlite would solve this problem.
Also, always wait until the top 6 inches or so your soil is dry before each watering / feed.

 

[slackerbri]

Will do, any suggestion on as how to add perlite to a planted pot without harming the roots or should I just go for that next time?

 

[Kr@kEn]

Well for now you can transplant into a bigger pot that has nothing but perlite in it so nothing but perlite surrounds the current root mass in a new pot. That way more air can surround the root mass. But yeah you don't want to upset the roots by tearing up the soil attached to the roots. But transplanting into a bigger pot of pure perlite for now would definitely help with the current problems.
When transplanting I recommend watering the day before transplant with a half dose of superthive. Then transplant the next day. When I do this the roots take off right away instead of being stunted. And the root mass also stays together and doesn't break apart during tranplant.
But in the future I recommend using at least 30% perlite by volume.

 

[MynameStitch]

There is nothing wrong with mixing coco and soil; what I mean is the mixture is 50/50 that is half which coco needs a soiless ph and a soil needs a different pH so I was saying it's a fight; if he added less soil or coco depending on which one he wanted then he could have a easy pH to deal with; but since he did half and half he has to find a medium.

It's too late to add perlite; that has to be mixed in the mixture before the plant goes into the pot.......

 

[slackerbri]

ok from looking at some more pics I have it looks as the coco is more abundant towards the center of the pot which makes me think I maybe mixed it not as well as I should have pre-transplnt but I mixed the last batch much more thuroughly. I am going to let it all dry out a bit and then inspect it, anyone think the PH is too high possibly?

Thanks everybody for your help and advice, its all greatly appreciated.

 

[MynameStitch]

WHat is your pH now?

 

[manchild]

Just from the looks of things you have nute lock.Your ph is out of whack.Try using some hydrated lime and then water once after that, then a tablespoon of epson salt to a gallon of water but I really would just change grow mediums.I would use the fox farm ocean mix.I think this would get them back on the right track.Purge my friend is sometimes the only answer.

 

[slackerbri]

Well a week and some later after I added some Mexican Guano, its seems to have helped considerably.