Necrotic spotting, Possible Cal def??

[Lilbud]

Right then, you asked for it, so here goes...

White Label White Diesel fem, 20litre DWC Bucket, Canna Aqua nutes, pH been running tween 5.5 and 6.0 EC 2.8/3.0 (at the moment which includes starting water EC of 0.4/0.6 ). roughly 17litres of DO per min going thru the bucket....so plenty of air, res temps max at 69/70, Sometimes had to use freezer blocks in the res to keep em cool.
Room temps, 78/82.... RH was quite low at the start but has steadly increased as they got bigger! usually tween 30/50 depending on outside weather.

Roots on this particular plant didn't get off to a great start, had major problems with my pH meter giving me false readings, and by the time I gotten a new one, slight case of Root rot had set in... gave her daily doses of H202 for about 3 weeks, which helped loads....and the roots seemed to catch up with her sisters....both seemed to be firing on all cylinders then until about 3 weeks ago, when I noticed Necrotic spotting on the older lower fans of one plant.....after having it confirmed as a Calcium Def, I started giving her a Cal Suppliment alongside regular nutes, using 1.0 ml per litre, so she was getting about 18ml every res change (weekly).....but the problem persisted, and it's gradually moved up the plant, and also started affecting the newer bud leaves :mad3:

(excuse the somewhat Sunburnt Cola...she got a bit too close to the light...)

http://www.homegrownbud.com/forums/attachment.php?attachmentid=16798&stc=1&d=1218670394
http://www.homegrownbud.com/forums/attachment.php?attachmentid=16799&stc=1&d=1218670394

[Shadows]

Hey LB, if you're using a Ca suppliment and the problem is continuing then the problem is not a lack of Ca, its an excess of P. Back off your nutes a tad man you've got lockout coming in fast, at least that'd be my perspective on it.

[Mr Burns]

Have you checked for spidermites Lilbud :shrug: Looks just like when I had the fookers.

Reason I say this is most of them specks are on the veins where they're commonly known to clamp on and suck/kill.

[Shadows]

Hey LB, if you're using a Ca suppliment and the problem is continuing then the problem is not a lack of Ca, its an excess of P. Back off your nutes a tad man you've got lockout coming in fast, at least that'd be my perspective on it.

Sorry I was off on my nutrient... Its K not P that has an effect on Ca




Potassium (K)
Action Mode
Helps plants overcome drought stress; improves winter hardiness; increased disease resistance; improves the rigidity of stalks; leaches from soil; mobile in plant
Deficiency
Reduced growth; shortened internodes; margins of older leaves become chlorotic and burn; necrotic (dead) spots on older leaves; reduction of lateral breaks and tendency to wilt readily; poorly developed root systems; weak stalks
Excess
Causes N deficiency in plant and may affect the uptake of other positive ions such as Mg and Ca
Comments
High N/low K favors vegetative growth; low N/high K promotes reproductive growth (flower, fruit); calcium excess impedes uptake of potassium


some more to chew on..
Magnesium (Mg)
Action Mode
Absorbed as Mg++; leaches from sandy soil; mobile in plant
Deficiency
Reduction in growth; yellowish, bronze, or reddish color of older leaves, while veins remains green; leaf margins may curl downward or upward with a puckering effect
Excess
Interferes with Ca uptake; small necrotic spots in older leaves; smaller veins in older leaves may turn brown; in advanced stage, young leaves may be spotted
Comments
Mg is commonly deficient in foliage plants because it is leached and not replaced; epsom salts at a rate of 1 teaspoon per gallon may be used two times a year; Mg can be absorbed by leaves if sprayed in a weak solution; dolomitic limestone can be applied in outdoor situations to rectify a deficiency

[Cranky]

looks like to much nutes to me..."stipullin"the stuff burnsy is talking about from mites is more of a powdery white looking shit.

just looks like classic nute burn to me imo;)

straight water id give um for the net 1-2 feeds.

hope yas sort it

cranks

[Foxy]

I agree matey, if you have a base of EC 0.4 (you're very lucky by the way ;) ) then getting up to EC2.8 seems shockingly high to me. :confused:

The hungriest strain I grown has never gone as high as that and that's with a base of 0.8.

Too high other stuff will easily lock out the bits they need. 2thumbs

[Lilbud]

Thanks for all the input guys 2thumbs

I've drained about 70% of her solution, and topped it up with pH adjusted water only....EC reads 2.0 on the meter, minus todays starting Ec of 0.5 it's only 1.5 , she's due a new res at the weekend anyway, so I'll see what happens tween now and then and adjust accordingly... she looks a tad sorry for herself, but she's still filling out!! :bananna:


got a crackin migraine comin on so apologies for the short reply!

[CB]

Hey Lilbud,

not a hydro expert or plant but to me a ec of 2 still seems high:) I use ppm here and don't adjust for the water ppm.... I just give the plant back what it ate and what it wanted on a daily base's ( I count my base water ppm in the factor not out)

I'm think'n a 70% draw off with a ppm that high still tells me the plant is puke'n it guts out in a bad way. I know you said you had different pheno's like and this one seems to be a lighter feeder to me. Flush the gal for a couple days with good water bro and watch the EC when you do.... if it goes up you know it was over loaded, and when it levels off she is good to go:D

I did spend some time in the OGfaq and shadows and cranky both have same info that I would post:)

tiss good to see ya about Lil..... been awhile 'eh


grow on :pass:

[WilliamClarkeQuantrill]

How much have you been feeding per gallon or liter? How much phos acid have you been adding per gallon or liter?

When the pH meter was giving false readings was it false on the low end or high end? Was it causeing you to add more phos acid than you really needed to get the desired pH?

[CezarCronic]

I agreed with Cranky and CB :D

To me is over feating necrosis , EC 2.8 is way to hight and pH 5.5 i think is a bit low .

EC 2.0 is the highest recommended in Hydro so i think still to hight ,

EC and pH levels recommended for hydro Cultivation :

Seedlings and clones EC= 0.40 to 0.60 ...pH= 5.7 to 6.0

Vegging EC= 1.00 to 1.25...pH= 5.7 to 6.0

Flowering 0 to 25 days ..EC= 1.25...pH= 5.7 to 6.0

25 to 15 days before harvest..EC =1.60 to 2.00..pH= 5.8 to 6.0

Last 15 days of flow ..EC 0.80 to 1.00 ...pH= 6.2 to 6.5

This numbest are the basic recommendations , i think you are a bit over in everything friend , those leaves are to dark green and the spots are a clear symptom of over feating necrosis :rolleyes:

My recommendation is to flush the root system with plain water pH 5.5 for 24 hours , them set your flow nutes level at 1.6 to 1.8 pH 5.7 and you 'll see the change :)

Flushing the plants will stop that necrosis from spreading forward , its clear is suffering from lad of nutrients .

[Foxy]

Yeah Dude, an EC of 2.0 in NFT seems well high, especially with a base of 0.4.

I can't remember the last time I got past 1.8 and that's with a base of 0.8. ;)

[CB]

Mg is commonly deficient in foliage plants because it is leached and not replaced; epsom salts at a rate of 1 teaspoon per gallon may be used two times a year;

hey bro where ya quote'n that from? I give the plants 1/2 teaspoon/gallon every water/feed.... like a pinch worth

not sure what they mean by foliage plants (leafy?) but MJ can handle it just fine at least once a week at 1/2 per

peace

[Lilbud]

Cheers for all the input, I've been feeling pretty shit the last few days, so apologies for not replying sooner!

Following the flush, EC rose after 24hrs,from 1.5 to 1.8, which may have indicated over feeding, but 24hrs after I topped her up with 3 litres of pH adjusted water, and brought it back down to 1.4.... it had dropped off to 1.0/1.2 :shrug: ...so she got a fresh res yesterday made up to 1.4 which has remained steady so far.... :watch:


I hear all your concerns about the EC being quite high, thinking about it myself I might have been inclined to agree, but with her sister absolutely lapping it up, and with only minor tip burn from the shooting powder, and others suggesting it's a classic Calcium Def...... I'm not entirely convinced ....:confused

I've trimmed a lot of the dead necrotic leaves off now and she doesn't look as bad as she did..... her main cola just seems to be getting thicker by the day!!! :wow:

[Foxy]

It's definitely Calcium deficiency Matey, no one's saying it isn't... ;)

What I'm guessing is its deficient in Calcium because your nute levels are so high that the ratio/balance of nutes and elements is getting skewed, which is preventing your plants from taking up the calcium.

Maybe... :D

[Lilbud]

It's definitely Calcium deficiency Matey, no one's saying it isn't... ;)

What I'm guessing is its deficient in Calcium because your nute levels are so high that the ratio/balance of nutes and elements is getting skewed, which is preventing your plants from taking up the calcium.

Maybe... :D

I hear ya Basil, but what I can't understand is, it started well before the nutes got so high :shrug: to me that says the problem was caused by something other than a high EC.

It may well have made it worse...you guys know more about this than me,....just trying to understand what caused it initally, so I can avoid it happening again! ;)

[Shadows]

Mg is commonly deficient in foliage plants because it is leached and not replaced; epsom salts at a rate of 1 teaspoon per gallon may be used two times a year;

hey bro where ya quote'n that from? I give the plants 1/2 teaspoon/gallon every water/feed.... like a pinch worth

not sure what they mean by foliage plants (leafy?) but MJ can handle it just fine at least once a week at 1/2 per

peace

Take ya way way back bro, Delta posted that about 7-8 years ago and while some things have changed, like a respectable Mg ratio, its typically all good information I've used as a basis for growing since I started.
It comes from a post I have at another forum that you know of, in their Library section, nutrients.

[WilliamClarkeQuantrill]

I don't think it looks like calcium deficiency much at all. ;) Looks like too much of something to me, hyperaccumulation. My number one suspect would be phosphorus.

[Mr Burns]

So any news Lilbud :shrug: Hopefully good news?

[Foxy]

Here's some Canna pics.

I guess we wouldn't be able to really tell what it was unless the leaves were left on to develop. :shrug:

When I was was battling with Cal def one thing that I noticed was even when I cured the problem, the spots still grew bigger along with the leaf.

[Lilbud]

Here's some recent pics...

http://www.homegrownbud.com/forums/attachment.php?attachmentid=17011&stc=1&d=1219361946
http://www.homegrownbud.com/forums/attachment.php?attachmentid=17012&stc=1&d=1219361946
http://www.homegrownbud.com/forums/attachment.php?attachmentid=17013&stc=1&d=1219361946

I haven't give her a total buzz cut or anything, just some of the bigger fans that had gone all Crispy and dry....

She does seem to be maturing, albeit slowly, I dropped the EC right down to 1.6 (1.0) after a flush and it has been rising slightly everyday since, so I've been topping up with pH adjusted water to keep it low.

As you might notice in the Cola pics, there is some damage to some of the small bud leaves uptop, but most of it is trim anyway so I'm not hugely concerned..... what I am concerned about tho is the lack of Trichs.....she's almost bald compared to her sister....and this is supposed to be a white strain ::shrug: :damn: would all this stress and shit cause that then, or could that be down to Pheno?

[majestyk5]

could be either

[San]

My number one suspect would be phosphorus.

I was leaning that way ;) Trouble is, once phos levels have effected Ca uptake, I've never been able to correct it, tho I have been able to stave off Iron def, which is the next logical deficiency ;)

This mite help a bit, more from hydrotops ;)

It is essential to good nutrient solution management that the strength of the nutrient solution (EC) is set to reflect the plants stage of growth (this is sometimes called Feeding On Demand)
When young plants are first placed on the system, the root growth is not particularly well developed. The nutrient requirement at this time is quite low. As the plants begin to grow, and the root system develops, nutrient requirement increases in relation to how fast the plants on the system are developing.
By careful monitoring of the nutrient solution on a daily basis, the grower can adjust the strength of the nutrient solution to maintain a good balance between water and nutrient uptake in the crop. Where nutrient strength is too great for the plants needs, there is a tendency for the EC of the nutrient solution to rise, which will require the addition of tap water to restore the solution to it's original EC. When adding tap water only, the grower is supplying additional calcium, magnesium and other elements, without balancing these additions with nitrogen, phosphorous and potassium, etc.

If this situation continues, excess magnesium and calcium will occur in relation to the other elements, leading to nutrient imbalance in the solution and eventually to nutritional deficiencies within the crop. In areas of hard water where large amounts of calcium and magnesium are present in the water, and at times considerable levels of sodium, this situation can reach a problem level within a very short period of time.
When adding topping up water it is also necessary to add acid to restore the pH to an acceptable level. This can cause problems with the availability of iron and calcium when phosphoric acid is used.
In a ideal situation with a balanced nutrient solution set at the correct EC for the stage of growth, it will be necessary to top up the tank with nutrient solution, not just tap water.
When using recirculating hydroponic growing systems, it is necessary to top up the nutrient solution from time to time to replace the solution removed by the plants. Often, as the level in the reservoir falls, the EC of the remaining solution will rise. This is normally due to the plants requirements for water being greater than their demand for nutrient.

Correct management of the nutrient solution can go a long way to ensure that as the solution volume in the reservoir falls, the EC will remain very close to the level set when the nutrient solution was freshly made. (Try to allow at least 10 litres of nutrient solution for every plant growing on the system).
The pH of the nutrient solution is an essential factor that must be monitored in all methods of hydroponic growing. Plants are able to absorb nutrients from the nutrient solution between the ranges of pH 5.5 to pH 6.5. Outside this range some nutrients may not be readily available to the plant. By running the solution pH within this range growers ensure nutrients are always available to the crop. As experience dictates, the solution pH can be fine-tuned to obtain the optimum results from the system.

Going back to the phosphoric accumulation thing, it's usually because high alkaline water (i.e. very hard) needs lots of acid added to get it within an acceptable pH range. You add back water that needs more pH down added, this can accumulate, skewing nutrient profiles.

This is where Nitric acid comes in ;) (one mite have to reduce EC a little with nitric)

High EC's can make the phos accumulation issue worse ;) You are effectively keeping the phos ratio even higher if the EC from nutes is too high to begin with, it'll cause much more problems in hard water as the nute profile is hardly ever bang on anyway.

Think of eating lots of salty food (high EC) you get very thirsty (water uptake increases) leaving an even higher EC in solution, or even saltier food to eat, where you want more water to drink - a vicious circle ;)

San:smokin:

[Lilbud]

Thanks for that San ;)

Certainly made things a lot clearer in this cluttered old head!! 2thumbs: ....guess I should have paid more attention in chemistry class, and I'd have known just how much the various chemicals/elements can interact/react with each other!

Been looking at RO MACHINE (http://www.progrow.co.uk/acatalog/info_1749.html) today..... actually are a lot cheaper than I thought to...so It might be a good idea if I wanna keep doing hydro.

[Cakes]

re nutes, this is what my understanding is-

mg goes hand in hand with ca and K due they are the nutes that the plant takes up passively. they are drawn up as the water evaporates out the leaves. first to arrive at the growing tip is mg, it is like the waxy coating.

17491
mg def. a spiral cracking a tomato from top to bottom.

and then comes calcium.

17490
ca def. always causes the round black rot spot on the blossom end of a tomato.

^^an irregular water supply can also cause those symptoms (possibly sans the entire spiralling thing).

once the calcium is there, it has been seen to actively usher potassium from one cell to another, through a little gateway that it makes; after it goes through with the K, then it closes the gateway behind it's self. and it can do that over and over again.

K makes the plant's cell walls and it makes sugar, which is the precursor to THC. K also makes the cell walls for the THC crystals.

as the sugar morphs, it also releases phosphorus. which phosphorus is a little electrical charge that is at the nucleus of every living cell.

So, the plant passively uptakes all of the above mentioned things and also salt goes up like that. the plant can use salt instead of K for it's infrastructure, up to 70% substitution occurs in the absence of adequate K. maybe good to know if u r interested in a low salt diet.

all other nutes the plant takes up aggressively and so can be mobile.

re the plant in question, idk. but it kind of looks like rust.

17489

Rust can go hand in hand with weak cell walls due to deficiencies and or water problems. especially water probs due to rust and disease proliferate mostly based on whether their spores can germinate.

The plants in the pix look a little overfed with Nitrogen and such lush bubbly growth can make a plant have weak cell walls, the infrastructure nutes do not have time to keep up. could a slight N overdose = not enough ca or mg?

the spots and discoloring pattern also looked just a bit like overwatering (which can be a form of nute def due to too much water = less nutes, same as the N theory i was talking about). if the OP had been having trouble keeping his res temps low, or if the leaves weren't so dark green, we might have considered this more seriously.

At first we were wondering a little if the spots began due to the h2o2. I recently tried using it in cloning water. and if i poured in quite a bit, then the leaves directly over the water showed necrotic spots like ozone poisoning. It appeared the oxygen going up into the air was oxidizing the leaves. and once those spots started, they didn't really stop, the leaf/leaves continued on rotting away although slower when i left out the h2o2.

even without h2o2, just pure moisture at the bottom of a plant can weaken tissue a little of course; also it can allow unfriendly spores to have enough water to germinate so rust could have started that way even if the plant didn't get degraded from the extra free oxygen.

if it is a rust, stuff like that (mold, fungi, blights, etc), once it is on the plant, it rarely goes away. Serious chemical treatments can make them seem to go for a while or they can be outgrown or arrested by providing ideal conditions but generally they will continue to advance and at every climatic opportunity they will surge forward with huge growth.

here are pix and info on various rusts. they look very individual depending on the plant and disease type but the prevailing characteristic is round red spots, hence it's name 'rust':

www.
ca.uky.edu/agcollege/plantpathology/ext_files/DiagnosticImagesWoodyOrnamentals.htm

cannabis is prone to three different types of rust. i got no pix tho and it's lunch time so ur on ur own. here is a list of the diseases they get:
http://en.wikipedia.org/wiki/List_of_hemp_diseases

RH was quite low at the start but has steadly increased as they got bigger! usually tween 30/50 depending on outside weather.When my moisture levels fluctuate is when my plants get disease here. a dry-ish spell brings it on and it might only be unsaturated less than 12 hours but it happens and then it stays. The first spot it hits is the 1/4 outer inch of leaf, just where a K def would show. The next thing I notice is a shiny coating starts to develop. and it looks like there is a sticky coating on the OP's pix. and it is a common thing in leaf diseases.

[CB]

Tiss my understanding as well cakes:)

good to see ya about.

grow on