Potassium deficiency or nute burn? HELP needed

[Mr Green Fingers]

Just reading back on your 1st post, your run off ppm does seem low for this stage and those black edges do look the start of potassium deficiency, do you have any kind of pk boost as I'm not familiar with the products your using?
There should be some experienced soil growers in here soon though so hold tight for there diagnosis as your girls dont look to bad at all so no need to make any drastic changes yet until someone experienced confirms your problem

 

[Kush420]

Just reading back on your 1st post, your run off ppm does seem low for this stage and those black edges do look the start of potassium deficiency, do you have any kind of pk boost as I'm not familiar with the products your using?
There should be some experienced soil growers in here soon though so hold tight for there diagnosis as your girls dont look to bad at all so no need to make any drastic changes yet until someone experienced confirms your problem

I fed yesterday with a more concentrated feed and got a 596 ppm run off (more acceptable for this stage of growth). I am leaning towards Potassium deficiency for sure. I suppose Topmax is like a PK boost...but what I did yesterday was added more Bloom nutrient to my watering schedule.

As I say, so far all I did with her was a light flush to get a reading of the root zone pH and ppms. After that only one more feed of nutrients same as the other girls im growing. The other plants dont show any signs of Heat Stress either, I know this one did but that happened a week or so ago.

Thanks for your replies though

 

[Kush420]

What kind of soil are you in ? Whats the PH of your water ?

All quoted in main post friend i've since moved the light 21 inches above the canopy of the problem plant. I have a GSC which is way closer to my light and she is doing great tho. I think the old issue needs to be less focused on in diagnosis, i was aware of the heat stress issues... its not the issue I came here to ask about really... The leaf issue with the browning is the key problem.

Thanks for your reply.

 

[Kush420]

Anyone else able to help with this issue? Seeing further signs after 24hrs of giving PK boost in the main vein of one leaf and now mid / lower parts of leaves also giving me issues.

 

[Slater]

possible potassium diff but I would wait for confirmation from @Waira or @Mossy on that... I've Still got my training boots on for diagnosing plants ... on the light hanging height and power you are to far away with having your QB's on half power (I grow with QB's)... You only need dim you lights in veg or if you plants have grown into them (5")...you are denying light in flower and we want as much as the plant can take for that all important yield.

wack that baby up to full power slowy over a few days for the plants got used to the extra light then start to move it closer to your plant until your about 15" away (you may get even closer depending on the plant).

 

[Kush420]

possible potassium diff but I would wait for confirmation from @Waira or @Mossy on that... I've Still got my training boots on for diagnosing plants ... on the light hanging height and power you are to far away with having your QB's on half power (I grow with QB's)... You only need dim you lights in veg or if you plants have grown into them (5")...you are denying light in flower and we want as much as the plant can take for that all important yield.

wack that baby up to full power slowy over a few days for the plants got used to the extra light then start to move it closer to your plant until your about 15" away (you may get even closer depending on the plant).

Yea, thats the thing... I have a GSC Auto which is now hitting 32 inches (83 cms) in height so she's pretty close to the QB as it is so i've got to trade off on that and the other two smaller girls in the tent. Tent is only 6ft tall so space is a little tricky. I had moved the light higher yesterday due to the issue with the plant in this thread. I do believe its a Potassium issue now because the leaves in the pic from yesterday crinkled up and dry today so they've been cut away from the plant.

I administered a 4ml,2ml,4ml (Bloom, Grow, Top Max) in 4L of water yesterday as well and fed that to her, effects yet unknown. PPM was better and pH remained about 6.55 pH. I will take your advice on board as best I can re the light but I have also got to consider the bigger plant being too close to the QB

Would be good for @Waira or someone better versed in deficiencies to chime in on these problems. Definitely feel like its got worse in 24hrs and not better though considering i've given as good boost of both Potassium and Phosphorus.

 

[Kush420]

@Waira any help please?

 

[Waira]

hey Kush--- weird symptoms here,.. those upturned margin "teeth" are usually a sign of light and/or VPD stress, but the tip necrosis is typical of K defc., not that both can't happen at once!
RH% and T seem OK though, so..... unless there's a strong constant breeze blasting the tops, I'm unsure about the curling.... K defc, is fairly common, especially with a mild nute line like BBz,... up your bloom some, or look into a PK booster of some kind and see if that halts progression,....

 

[Kush420]

hey Kush--- weird symptoms here,.. those upturned margin "teeth" are usually a sign of light and/or VPD stress, but the tip necrosis is typical of K defc., not that both can't happen at once!
RH% and T seem OK though, so..... unless there's a strong constant breeze blasting the tops, I'm unsure about the curling.... K defc, is fairly common, especially with a mild nute line like BBz,... up your bloom some, or look into a PK booster of some kind and see if that halts progression,....

Hey @Waira Thanks for chiming on on this thread, very grateful for your input!

There is 2 issues, the first issue was indeed VPD / Heat related and happened probably 2 weeks before this K deficiency even reared up... So that was an issue that was rectified and obviously once they curl they often dont come back from it with Heat related stress and or light stress as im sure you also know

I agree with the fan thing, i've also corrected this and moved it to blast an alternative way. For the nutrients i am now doing 8ml of Bloom and 8ml Topmax and 3ml of Grow into 4 Litres of feed from today. Will keep an eye on this over the next few days and drop an update here if anything improves or worsens.

Thanks to all who have added their input to the issues. Appreciate it.

 

[Waira]

Cheers bud, I see my mate TGB has cleaned up the crap left by that wanker and his retarded BS advise, which stained the carpet with in several other threads as well! - ... I swear, it's like a crackhead got hold of a keyboard!

yeah, the LED light intensity/overload thing (not really heat, just photon blasting damaging the "machinery" in there) plus VPD, other potential tangles can make for odd symptom,s tougher diagnosis too,... what's happening with heavy transpiration tared driven by borderline VPD, low RH%, it that the water AND nutes are traveling the same highway, so as the plant is hauling water up like mad to keep pace with transpiration, nutes are coming with it,.. right at those teeth tips are larges vessels/plumbing, to often this is where a nute ion buildup will show by burning, when lower leaves less exposed are fine,.. heavy air movement across the tops magnifies this significantly, faster evaporation/transpiration, more "pull" from roots up and it snowballs from there! If symptoms aren't progressing, that's the tell....the bitch with K is both defc and minor toxicity show the same-- burned teeth tips! So, given your mild nutes, I'm figuring it's a lack of, even with the other factors... let's see what a couple days brings,...