Leaves splotching, yellowing between veins

[LEDman]

This thread is a sequel of this one: Drooping Leaves Galore / pix - for those interested in the history of this.

Indoor MediBud Soil grow, 6x90W LED + 6x75W CFL @ 6500K, 7th week since germination, repotted two days before these pix were taken. Canopy tent temperature is between 21 - 23°C, RH ~45-50%.

I nuted them at 1/4 strength after repotting, since I figured the new promix soil would give them ample nutes for the start.

My thought is that I gave them too little overall nutrients, as the soil pH is a good 6-6.5 in all the plants showing these symptoms, so no nutrient lockout in progress. Genereally, I see signs of Mg, K and P deficiency here to name the most prominent. Anyone disagree?

The plants are doing well overall, but this definitely looks like the beginning of major trouble, so I would very much welcome any relevant input on this!

 

[GigaGrew]

man i wish i knew more. this is why im fast going off soil.

im guessing the root ball kept hold of the old soil, then new soil around the edge and beneath?

fresh nutes on the outside and barren mud in the middle and a poured on nute solution, it must be nearl impossible to be sure what your plant is getting day by day =/

looking forward to the day i find my 'perfect' method so i can shout it from the rooftops

hope your little ones get well soon, ill send grapes and flowers you get them a nurse

 

[LEDman]

Thanks man, I'd have gone hydro or aero too, but this is my first grow. Soil forgives a lot of things that the advanced techniques do not. Once I got this all sorted out, I'll definitely move on. The ability to immediately control what your plants get instead of a mix of guessing and measuring, then waiting for a full three days to be able to water again trying to correct what you did wrong three days ago... sounds like heaven.

 

[GigaGrew]

im going to try growing using coco as soil. its one step in the right direction

 

[LEDman]

You know, I think my next batch is gonna be 50% perlite/50% soil. Getting the hang of it and being able to control the variables more tightly is gonna be interesting.

I feel like back in driving school, learning to park correctly. Today (not gonna disclose the number of years later), I'm the messiah of parking.

I'd love to reach that level of confidence with growing MMJ, and I think the way to do that is to cut out all the ballast and unnecessary variables, meaning that eventually, I'll go aeroponics or hydroponics.

 

[McCrackin]

That's p def from either over water or suffocating roots or ph whack. I would move to baskets that drain good, flush with kelp powder and let dry out. No nuts until you see n def. Also cal mag iron about 50 ppm total in flush.

 

[LEDman]

Thanks, McCrackin. The baskets drain well, the soil is an already perlite-containing "promix" with coco fibers and pre-fertilised soil that I added approximately 15% additional perlite to. I don't think a flush will help here, there's no salt buildup yet and due to my under-nuting, no toxic level can have been reached yet. I think I'll give them the regular dose described in the nutrient chart for my product with the next watering.

Man, do I hate waiting...

 

[GigaGrew]

curious, did you flush the hell out of the coco before using it?
they can contain an awful lot of salt even the 'good' ones so these guides tell me anyway.

 

[LEDman]

Sorry, i put that a little ambiguously: The promix soil I used comes already mixed with perlite and coco fibers. I simply mix between 15 and 20 % additional perlite in for better drainage and air retention.

I'm too new to fuck around too much with creating my own soil mix.

 

[McCrackin]

Thanks, McCrackin. The baskets drain well, the soil is an already perlite-containing "promix" with coco fibers and pre-fertilised soil that I added approximately 15% additional perlite to. I don't think a flush will help here, there's no salt buildup yet and due to my under-nuting, no toxic level can have been reached yet. I think I'll give them the regular dose described in the nutrient chart for my product with the next watering.

Man, do I hate waiting...

I respectfully disagree. With kelp powder in flush and low 50 ppm of micro, you are reseting the "flavor" of the soil for the plants. If you flush at say 1.5 gram per gallon, the soil will be conditioned for drying out without killing anything. My 2€.

 

[LEDman]

I don't think I really understand you - my plants *must* suffer from a deficiency *not* caused by too high a concentration of nutes or lockout (soil pH is 6-6.5 and the plants were consistently underfertilized, roots are doing great, and I know what whack roots look like ).

So even if I had kelp powder (I can't find a source near me at short notice), what good would flushing and further depriving the plants do? Next watering will probably be tonight, so I gotta decide what to do...

Please bear in mind that only three of 13 plants show these symptoms in just a few leaves, so I'd try to do something not overly dramatic, right? Thanks for your input!

 

[McCrackin]

First kelp is set at n-P-k that emphasizes p and k. So flush with these will add something, also the kelp powder helps balance ph and buffer soil bacteria. I say it's a soil problem and this type of flush will reset your soil. Second, if it's a suffocation problem, then potash will help.

The splotches like that happen when plants have breathing trouble in roots. So running a lot of water through them if draining good will help clear the roots of moisture that lacks o2 or is chemical.

Finally if it's only a few plants it's either drainage or they are sensitive to something.

In my experience, with good drainage, kelp flush is my goto resource for everything, my step one in fixing plant trouble. Basis for fixing other stuff.

 

[LEDman]

So, I have no kelp. I have, however, a nutrient solution that has enough p and K. The soil is good and fresh, it's not the problem. You focus on pots and soil that drains well. I have both. My roots CANNOT be suffocating (no overwatering, the soil is just bueno) and I CANNOT have an overferting problem here, due to me not fertilizing nearly enough - I double-checked the nutrient schedule, too late.

Sorry if I sound frustrated, but you're basically telling me to go to the moon when I don't have a spaceship.
I need to know how to fix my problem with the resources at my disposal. Do you think that in lieu of flushing with kelp, simply giving the plants the nutrients they need would be a step in the right direction? I am one confused noob.

 

[McCrackin]

Ok put 10 gallons of water through each pot in a flush with that soil that drains so well, then on the last 1/2 gallon do the npk at 5-6-7 nutes at tsp/gal. Then let them dry out almost completely, until they are light and none of the top two inches of soil has moisture, then water em light and add nuts at tsp per gal.

What I am saying is only add a tsp total to the last gal. What I would use is superbloom from lows for like 6$.

Oh and then I would also get some azatrol and spray the shit out of soil and plants in veg to get anything you haven't seen.

 

[LEDman]

Okay thanks, that is something I can do. I'll wait until tomorrow to procure the necessary items - difficult on a lazy sunday. I will, if I may, use 5-5-5, as this is what I have. I'll post updates during the next days to see how this will turn out.
*fingers crossed*

 

[LEDman]

Hey McCrackin, the last watering at your recommended nute strength seems not to have hurt. The few damaged leaves stay as they are, new growth is vigorous as ever. I had to raise the lights a bit, the White Widow (which is still in unwanted flowering, dammit) and the three Super Silver Haze (these four plants were never showing signs of def.) are really pushing the sky. I'll post pix tonight.

 

[McCrackin]

Ok so they should take a few days now without water, but what is really nice is when you think they need a few days and you show up on day two and they have sucked up the water at alarming rates.

You want to now dry these out. i would go for three days without water and check them... the weight of the pots should be light when you pick them up after drying out.

If you check them and they are not drying out at the same rate, i would suspect the ones with problems stay wet the longest... what i would do is check them a few times each day and if some look dry on day two, put a 1 cup of water at the base of the ones that dried the fastest... to let everything get real dry in there before moving forward, you can ilk the ones that dry out with a cup or two at the base while the others dry up.

Once you have a garden that is dried out, (not drooping leaves though, if the plants don't keep their vigor, all will be wasted) so once the garden is dried out, all your plants are dry, then the next water will be at 1.5 tsp per gallon of nutes. you should by then have a good idea what plants are water hogs and what plants are water sloppy. Give water sloppy plants less water and try ad coax them into larger watering requirements.

from here you will only then add nutes at 1 tsp per gallon for like two weeks every three waterings.

oh and while you are drying the plants out above, you need to scope them for spider mites and soil bugs. and because i roll that way, cut off all the dead or ugly leaves on them so they are pretty again. I bet you will find some bugs, but if in veg, you can spray them hardcore.

ltr.

 

[LEDman]

You bet. I always take care not to overwater them - in fact, I've been a little too harsh with them at times until they were bone dry; that really hemmed their vigorous growth and will not be repeated.

I'm also under the impression that the nutes I'll use are pretty low in potency, so I'll make a trip to the grow store and get something better for the rest of the veg phase. The way these babies keep growing, I'll put them under 12/12 in a couple of weeks before they outgrow the 2x600 HPS I have in the flower room.

Thanks again for all your input, it is highly appreciated.

 

[LEDman]

Quick update, the rewards of your input: 6x90W UFO LED - 2x600W HPS Soil Grow - Medibud - Super Silver Haze - WW

 

[McCrackin]

looks good and you are in veg so get some neem also...