Cant Properly diagnose plant problem..

[cesartime]

Here goes, ive been trying to trouble shoot this damn plant to no avail, so i figured id ask the professionals for help..

Unknown local clone, 2.5 weeks into flower. Feed is 5.8-6.1pH and approx. 675ppm. Lights -3x600 about 8-10'' from plants hung vertically. Temps are 65ish during lights off and up to 80 during lights on. Humidity is kinda low, swinging from 25% to 40%.

Up until this past weekend I was feeding 800ppm but that kept me giving me dark green clawed down leaves as can be seen on the top of the plant, so I took the feed down to 675ppm to see if that would help what I thought was a nitrogen overfert problem. At 800ppm I was also getting the larger fan leaves on the bottom of the plant to start spotting heavily, go yellow and die off. I thought that was signs of me overferting and locking out various things the plant needed.

So now fast forward a week of feeding @ 675ppm, and now it looks as if the problem is getting worse/changing to a genuine defficiency?? As you can see in the whole plant shot, the plant is getting lighter from the bottom up, and those damn pesky spots on the leaves are showing back up.

So I ask, what is the problem, and what can I do to correct it? In the same room I also have some sensi star plants that dont look anywhere near as bad.

Ive tried flushing the plants hoping i could wash out whatever potential lockout I had, recalibrated my ph/ppm meters repeatedly, cleaned out my res, to no avail.




What Gives??

 

[MynameStitch]

WHat pH is your plants at? What is the run off?
You using coco?

Also yes, you did have a nitrogen tox problem, you fixed it and the problem looks to be a little over watering, how often are you watering?

How often are you feeding your plants and what are you feeding them?
Those temps are cold, for one cold plants slow down eating there feed when temps are cold, keep the temps stable and don't let it jump 15 degrees everynight.
don't let it get under 70F.
How big of a bag are they in?
Are you using any pH adjusters?
Are you using tap? RO? distilled?
The other clone that is not showing problems may be more tolerate to pH swings and or less/more nutrients. Each strain is different so that is why it's doing it and the other is not showing as badly.

Can you take another picture of the problem close up?
You may either have a pH issue, or with the plants getting bigger and you flushing them they may need a little more of certain kind of nutrient, not more food altogether.
I can see the plant soon starting a N deficiency, that is why the leaves are lighting up; give or take a week they will start to yellow.

As for the spots, I can't see them in the picture. without knowing your runoff I can't say that is not the problem or that is not what is causing it. Are the spotting in the leaf veins?

 

[cesartime]

Thanx a trillion for your reply.

Plants are in coco, 1 gal gro bags. As for ph adjusters I do have to add a small amount of GH pH down to lower my feed solution to 5.8 when i mix my res. I am using tap water, 110ppm out of the tap. I dont beleive overwatering to be a problem as I water every other day with 675ppm solution and my bags never stay saturated more than a few hrs. I water when the lights come on, and by the time the lights come on again for the next light cycle, the bags are noticably lighter. These plants are drinking water fast as all hell.

Runoff, comes out @ around 400ppm/5.8pH. im measuring the runoff by pouring plain pH adjusted water (about 120ppm) into the bag and catch the runoff in a cup. If i need to be pouring my 675ppm feed solution into the bag and measuring the runoff of that please inform me so i can give it a run tonight when the lights come back on.

And the spots, sorry i didnt give a more detailed pic, but if you look closely at the whole plant picture the most yellow leaf on the bottom right side of the plant is showing the spots, they are not in the veins of the leaf, they are all over the leaf, brown spots.

Sorry, I cant take any pics until later tonight as it is lights off at the moment, but when I can get back in there ill make note of all the things you asked and reply back..

I do have a pic of a sick leaf that looks similar to what mine are doing now. this leaf is from the same plants, just in veg...


Thanx again for your assistance.

 

[cesartime]

Heres a Picture of said leaf..

Heres a Picture of said leaf..

Nevermind waiting till lights come on, I went and grabbed one of the affected leaves from the plants in question, here is a pic of the most yellow leaf on the bottom right of the whole plant that I have pictured above..

 

[cesartime]

Finally, here is my feed regimen.. Right now Im using CNS17, I use it in veg and in flower, I dont see these same problems in veg, and I had similar issues with the plants in flower when I was previously using PBP pro. Also, since ramping down my feed I added some b'cuzz PK 13/14. So what im giving the plants is: 110ppm tap water that i let sit out for a day before i add nutes to help the chlorine evap off, about 500ppm of CNS17 bloom, and then the last 150ppm of PK 13/14. And the GH pH down brings the ppm to around 675. Thats all that goes into my res to result in the 675ppm feed.

Finally, do you suppose my low humidity could be to blame?? I can feed this clones mom up to 1kppm and have nice green lush growth. Its just when i move the plants to the flower room that all hell breaks loose. Im gonna get a humidifier some time this week hopefully so we will see how that goes.

Now that I flushed, ramped down the feed, and am now seeing defficiencies should I bump my feed ppm back up, using the b'cuzz PK 13/14 to up my potassium and phosphorus while feeding low ppm of my base CNS nute? And if so, what ppms of the various ingredients should I add?

 

[cesartime]

Ok, just checked runoff by pouring 1 gallon of 5.8ph 120ppm flush water through the 1 gallon grow bags of coir.. After leaving my pH and ppm pens in the cup of solution for 5 minutes, my results are: 580ppm 5.8pH.

Im gonna up my feed tonight, back to 800ppm. To acheive this ill use: 110ppm tap water, 650ppm of CNS-17 bloom, and and about 125ppm of PK 13/14. and the GH pH down will bring me right to around 800ppm.

Ill hope for the best...

 

[Weedhound]

Are you overwatering that plant by any chance? coco has so many weird little quirks that I don't understand. It's as though coco can't decide whether its a soil or inert medium.

To me it just looks overwatered for some reason. How often are you watering?

 

[KABBAGE]

Looks overwaterred/underwaterred/cold?

 

[MynameStitch]

Yes, you are over watering and since it's only got 580 ppm, increase your dosage a bit, they are hungry.

I would try it around 700 first then go from there.

THey are being over watered and this does stop the plant from absorbing nutrients properly, careful with your waterings, or the amount you use each watering. You want some run off each watering.

 

[cesartime]

Thanx for your replies stitch, but now i have 2 more questions hopefully this will help me understand more whats going on with my plants so i can read them better:

In your first reply you said that I did indeed have a nitrogen toxicity problem and that I fixed it. My question is, what exactly are the signs of me having fixed it? The fact that the lower growth isnt going dark green and clawing up like that? When trying to correct a defficency/lockout by flushing the plants, how long should I wait to see new growth improvement?

And secondly, when attempting to increase the ppm of my feed solution, how much should I raise the ppm by each time? 50ppm, 100ppm, 200ppm?

Is the increase of 200ppm or so going to be overloading the plant? Or should I go with a lower number to ease the plant into a stronger feed?

Basically, what im asking is: when trying to dial in a plants feeding needs, how much of a ppm increase should I use, and how long after increasing the ppm of my feed solution, should I wait to see results?

Thanx a million.

 

[MynameStitch]

You fixed it by backing off your amount of nutrients you were using.

It depends on the situation of what was causing the lockout/deficiency problem. If you were over feeding like in your situation, depending on the severity, backing off the nutrients and a flush/frequent watering will have solved the problem.

It can take awhile or quickly depending on if your mixture is soil/soiless, soiless mixtures take less time to recover, around 4-5 days where soil takes up to a week to start to show recovery, soiless takes a week to recover in a situation like yours that is.

All problems depending on how bad it is would take longer/less time to recover though.

You want to go around 100 ppms at a time, this gives you a chance to know if it was too high and how much you need to lower it, 200 is too much higher of a jump, you slowly increase it, unless you know the strain can handle higher amounts of nutrients than 200 will be alright, but you still got to be careful depending on what your PPM's is already set at. You should always start at a lower number to feed the plants rather than hitting them with a high dosage, this can cause stunting and stress, roots take time to recover when they have a burn.