Light burn or deficiency

[smokingdog]

If the pictures have come out pls take alook an tell me what you may think it is,im thinking its hot spots bleaching the leaves, it's happening in the middle only and only on the top few leaves,i have higherd the light noe to 16" from 12",im sure one of the plants have a calcium deficiency she's 5ft 11",they are on 1ml a liter of the new shogun nutrient range of cal-mag, silicon, 2ml a liter of boost an 1ml a liter of pk 9/18,i fill a bucket up to 8 liters(2 gallon) an i also feed dutch pro A&B bloom at 10ml to 8 liters.

 

[maimunji]

Nute burn. Salt build up or your ph is off.

 

[CaliVeganix]

Honestly I would agree with nute burn except it's only on the outer edges of the leaf and the whole leaf got discolored along with burnt edges implying a lack of nutes. So I'd say it's a deficiency. Potassium specifically. Could be caused by lack of K in feeding schedule (pretty unlikely), or like the other poster suggested (and is most likely correct about) ph is off and has caused a salt build up/nute lockout. Flush with plain water (if soil/soil less) Ph'd at your mediums optimal ph range and feed plain PH water until you see new growth (hope its not in fowering as those leaves wont recover)....if hydro change out res to fresh RO water ph'd at 5.6 until you see new growth....if you think you overdid the nutes just add some clearex or one of those flushing solutions (gh makes em along with others). Theyre supposed to have positivly charged ions that the built up salts attatch to. And in either situation, if you feel you underfed K, do a kelp foliar spray (lights off and not in flower) and add kelp into your plants feeding schedule. DONT DO UNLESS POSITIVE YOU UNDERFED K. Fwiw, not very likely, It COULD also happen from too much calcium (I was told it's CA that can lock out K and viceversa; N locks out P and viceversa; Mag locks out Ca & Iron if your tap water is really hard and/or you feed heavy/ammend your medium with lots of calmag it COULD happen but again unlikely. I'm posting some pics of potassium deficiency right now

 

[smokingdog]

Honestly I would agree with nute burn except it's only on the outer edges of the leaf and the whole leaf got discolored along with burnt edges implying a lack of nutes. So I'd say it's a deficiency. Potassium specifically. Could be caused by lack of K in feeding schedule (pretty unlikely), or like the other poster suggested (and is most likely correct about) ph is off and has caused a salt build up/nute lockout. Flush with plain water (if soil/soil less) Ph'd at your mediums optimal ph range and feed plain PH water until you see new growth (hope its not in fowering as those leaves wont recover)....if hydro change out res to fresh RO water ph'd at 5.6 until you see new growth....if you think you overdid the nutes just add some clearex or one of those flushing solutions (gh makes em along with others). Theyre supposed to have positivly charged ions that the built up salts attatch to. And in either situation, if you feel you underfed K, do a kelp foliar spray (lights off and not in flower) and add kelp into your plants feeding schedule. DONT DO UNLESS POSITIVE YOU UNDERFED K. Fwiw, not very likely, It COULD also happen from too much calcium (I was told it's CA that can lock out K and viceversa; N locks out P and viceversa; Mag locks out Ca & Iron if your tap water is really hard and/or you feed heavy/ammend your medium with lots of calmag it COULD happen but again unlikely. I'm posting some pics of potassium deficiency right now

Definitely not a ph problem an i doubt very much it's nute burn either ec hasn't been over 1.1(ppm 550) due to the pk 9/18, an yes im in the 5th week of flowering, im dam sure it's light burn an lighr bleaching the leaves, it's only centered were the lights hot spots are,the buds are pileing the weight on.
1 of the weaker branches off another plant out the way of the hotspots is being supported by a plant affected by the hot spots has the same affect on that 1 branch, the rest of the plant is perfect.

 

[CaliVeganix]

Damn just noted they were in flower damn....only looked at leaf pics...same advice (minus foliar) but use plain water for ONLY a couple of feeds to correct the PH and/or build up, then 1/2 strength nutes (since your a bit along already), and then full strength the feed after that. Here are the K deficiency pics though. Your in flower so it IS possible you are overdoing P and underdoing K (but check ph/build up first). And also with light burn the burns are more random streaks on the leaf where it got the most light (along with your buds starting to bleach)

 

[CaliVeganix]

Just saw your reply. If Ph is fine maybe it is k def. Sadly I'm going through some light bleaching/slight iron deficiency for the first time and can show you even at week 2/3 you will just KNOW. Here's my sad girl from too much light (she's bouncing back though underneath the bleached tip by day 16). Could you take a pic of the top of the bud away from the hps light so we can get a true color? Also for what it's worth the buds bleached before my leaves showed any damage so it really doesn't look like bleaching. You'd get chlorosis on the upper shoots like I did before you see real "burn".

 

[smokingdog]

Bang right there my mate,your a star im gonna give em a flush next time the light gose on,it's only got another 2 hrs of light left so tomorrow at 3pm when it gose on im gonna be there with ph'd water to flush em

 

[CaliVeganix]

Rereading your post I think you just solved your own dilemma my friend....greater light intensity means more photosynthesis/ more NUTE UPTAKE! Imma soil grower so maybe a hydro guy can chime in but I believe by week 4-5 of flower your PPMS are supposed to be up to 900-1200 ppms. Their STARVING for potassium! Look into it in case I'm wrong and one of the hydro guys doesn't swing by but I'm pretty sure your pretty low bro

 

[smokingdog]

All me bud sites are tied up but im sure i can sort something out for you tomorrow, it's late here in the uk it s 00:55am if i go in the bedroom now an open that tent an wake up the wife she would kill me,the noise of the extractor an intake don't wake her cause she had me spend a fortune on silencers for em for both ends of both fans,gotta say though im glad i did, there are super silent now i can just hear a small humming noise.i will definitely get those pictures up tomorrow for u

 

[CaliVeganix]

And thanks buddy, just look into that ppm thing before you start flushing because those numbers do seem low. Usually ppl overfeed rather than underfeed so that's why I initially recommended flush. Your ppm levels changed my diagnosis but again, when it comes to hydro, I could be off. Either way glad to ease your light burn concern. Happy growing

 

[smokingdog]

You might b wright there,an yes im a soil grower

 

[CaliVeganix]

Cool, yeah definitely don't want to piss off the misses lol. It's 5:00 pm in california so I'm barely about to hop in the garden. Looking foward to those updates though.

 

[CaliVeganix]

Dude ppms aren't really used for soil, that's why I assumed hydro. Are you organic? If so ppms don't really register organic matter. And your nute levels could be way whacked..What/how much nutes are you feeding? And at what week in flower? What's your PH going in? What's your runoff PH? Soil I know pretty decently lol answer these and I can give a solid theory...im all over the place in this thread lol now I know why the ole posters in the old threads used to ask for a BUNCH OF info lmao

 

[smokingdog]

I do usually have the feed alor higher but i just changed over nutrients to the new shogun range an the pk 9/18 says to lower your main a and b feed by 25 to 50% so now i only but 10 ml of each a an b into 2 gallons of water (8liters) i used to put 30ml in but since i started using the pk i have lowerd the feed to 500ppm, i been growing 10years now an i have never used pk before so it's new to me,im in a dilemma ere now i don't know if im iver doing the k or just under feeding through paranoia of nute burn an over doing the pk cause it's in the feed as well,plus they had advanced nutrients B52 an that got 4% of k in it they had it for a about 3 or 4 feeds last week with it's normal feeding schedule so that's why there may be to much k showing up,after a noticed the amount of k i had put in i put the plants on a 6.6 ph water feed for 2 feeds an cut the B52 out an started put the pk in at 0.2 ml a liter, tonight i the ppm i gave 3 that needed watering around 400-450ppm in the uk it's a ec of 0.9.

 

[smokingdog]

I got a few dwc oxypots that's why i have the ec/ppm an ph meter i just tested the run off an the ph,d water that i put through her,o don't bother when i put the fed an additives in at all but i have taken the ppm just to see how high or low it was,I've never had to do it before

 

[CaliVeganix]

So I looked at your nutes and their npk values, their feeding schedule, and the dosage your giving them. The recommended feeding schedule seems PLENTY high in potassium, but the amount your putting on the other hand, not so much. The recommended amount for 4 weeks in flower is 16 ml/per gallon of EACH part. So 32 ml of "A" and 32 ml of "B", if your using 2 gallons at full strength. At 25% less that would be 24ml "A" & 24 ml "B" for a 2 gallon mix (48 ml total). If your running only 10 ml of both "A" and "B" (20 ml total) your only giving your plants about 30% strength nutes...about 45% less than they recommend if your running it with their Pk booster..using coco nutes in soil with a 6.6 soil is another story. It's a bit long winded so bear with me, will have it up sometime tonight after I finish in my garden.

 

[CaliVeganix]

And if your were only using 15 ml of each, 30 ml total, then you've been feeding at half strength the WHOLE TIME which might explain why it got so bad as you went into heavy flowering and nutrient needs increased...

 

[CaliVeganix]

Also I'd recommend switching to a PK booster higher in P than K since your formula is high on K at full strength already with only a little P. Especially when you consider how little P they've been getting from that formula at 30% and the fact cannabis needs equally high ratios of P and K during flowering weeks 4-7. Some people even say you need MORE P than K. Here's a thread about the debate with some great info on the topic https://www.icmag.com/ic/showthread.php?t=191007&page=19

 

[maimunji]

Im sure you will find answer in you run off ppm what happpening there?

 

[smokingdog]

Out of light pictures

Out of light pictures

I have flushed them out now i got 4 left to do