Yellowing tips and spots (Flowering)

[DerWizard]

hi everyone, didn't want my first post to be in the Infirmary but here i am.

So i have been having some yellowing tips and spots on my beauty this passed week, and its slowly getting worse.

Grow info:

SOIL:

How long has this problem been going on? around a week, advancing pretty slowly.
What STRAIN are you growing? Unknown seed (some dominant indica by the looks of it)
What is the age of your plants? Sprout at 01/01 and Flowering since 08/02 - middle of week 5 of flowering.
How Tall are the plants? it uses about a half of the growing medium (about 80*40 cm and 50 cm high)
What size pots are you using? 12 Liter pot, which might be a little small for the size but i'm not sure. (too late to move anyway i guess)
What substrate/medium are you using? What brand of soil mixture are you using? No idea, its what was suggested by the growshop i bought from. (for cannabis)
What brand Nutrient's are you using? Growtek Solo-tek bloom. (Growtek Solo-tek Grow when it was veg)
How much of each nutrient are you using with how much water? about 3-4ml per liter of water
How often are you feeding? every 3 days. - every watering (this might be a bit much as i discovered lately, i could use some advice on how to water in Flowering with these nutrients)
If flowering, when did you switch over to using Bloom nutrients? exactly at 12/12 change. 08/02.
What is the TDS/EC/PPM of your nutrients used? i don't check it.
What is the pH of the "RUN-OFF"? i figured this is the first thing i should have done but i don't have meter, ill get one tomorrow and update. (water here is about 7 by some strips i used.)
What method of pH test was administered? Using Strips? pH pen? Strips which are pretty old and bad, ill buy a pen tomorrow.
How often are you watering? 3 days.
What size bulb are you using? 250W metal halide
What is your RH Factor? (Relative Humidity) its between 40% to 50% usually i don't control it.
What is the canopy temperature? about 20-25 C
What water are you using? Tap water.

So i started giving only water since 2 days ago and also been reducing nutrients by half before that twice, no improvement.


These are two pictures of the same leaf 3 days ago and now:



And three more general ones:



My theory is that i gave too much nutrients and this made some of the yellowing tips and blades, but i think it might have also caused calcium deficiency because of the spots.

How should i proceed folks?

 

[DerWizard]

Also forgot to mention it appears to some degree in most leaves on the top of the plant.(i assume these are new young leaves mostly?)

 

[DerWizard]

OK so a quick update, i bought a good reliable pH pen and a EC Meter and it appears the pH of the tap water here is about 8.0, i will lower it to about 6.0 with pH Down from now on, hopefully the problem will stop getting worse. (EC is 0.3 which is fine)

I will start feeding again once it stopped, for now i gave tap water with pH 6.0 and like 1ml per liter micro nutrients.

I've also probably fed too much in general (maybe even twice too much), next time ill feed to get to about 1.6-2.0 EC.

 

[Douglas.Curtis]

Pictures in white lighting would help immensely.

 

[DerWizard]

Still getting worse, quite faster id say.

here are some pictures from today with white light, sorry for the yellow ones didn't think of it...



I honestly don't understand whats happening, this grow was absolutely perfect until now, anyone has any advice? how could i figure out even?

After i gave only water with micro yesterday(pH 6.0, EC 0.35 with micro), the runoff water pH was 6.0 as well, and the EC was about 1.6. (obviously there's still some nutrients in the soil but doesn't seem like too much)

Maybe it needs the regular nutrients back to stabilize, maybe it wasn't much of over fertilizing but some specific deficiency because of the pH from my tap water?

Any advice or ideas would be appreciated.

 

[DerWizard]

Another important piece of information.
The regular watering with nutrients as i used to give has pH 6.3 and EC 2.2.
So i assume we don't have a pH problem generally. (by luck)

This seems more like a potassium deficiency now, i don't see exactly why, but i think it can happen even if your nutrients are balanced, maybe something got built up in the soil and its blocking it, like sodium even? if this is the case it should have gotten worse with what i did until now, pretty consistent i think.

 

[windycitysmoker]

To much food it seems IMO new leafs are burning up

 

[hubcap]

seems like you got the pH numbers back in order.
for some reason my gut was telling me magnesium def. could be wrong tho.(OR the feedings at 8pH locked some nutes up...and uptook too much of others)
these can be tricky....

I dont think the crispy leaves will miraculously turn back to lush green, so, leave them on it until she doesnt seem to need them anymore and remove them if you feel the need.
Looks like youre to the point where you dont need anymore N in the mix, so, losing a fan leaf or three is no big deal to the plant at this stage.

for me, i find its better to slightly underfeed than to get aggressive in the feedings. Makes fixing problems at bit easier.....

keep us in tune....

Edit:
4-9-8 seems pretty tough for a flowering girl. in soil....imo.....half the feed (or cut it (N) entirely) until youre certain the soil is flushed and stable)

-cap
(what do I get for this being my 1000th post?)

 

[windycitysmoker]

http://www.kindgreenbuds.com/cannabis-grow-bible/plant-problems-and-how-to-solve-them/
This should help u

 

[DerWizard]

Thanks for the info guys, i think windy's link provides stronger evidence for potassium deficiency.

Flushing seems to be common practice in soil grows so today i decided to flush even though it was pretty hard with the scrog and everything tied to it.

I flushed 30 liters tap water until the EC of the runoff was 0.4 and then i gave it 3 liters pH 6 water with about half of the feeding she used to take and in addition a potassium additive for this period in flowering.
(2 ml/l Growtek Bloom NPK 3-8-8 and 1 ml/l Growtek heavy bud NPK 1-0-3)

Also a small note, the humidity got a bit higher this week to about 60%, i don't control this but i was wondering whats the effect of this.

I'll keep updating.

 

[maimunji]

You are almoust right thats k def not p.
Edit: Ops just read you said potassium not phosphorus so you are right. Good luck

 

[DerWizard]

Hi, definitely still getting worse despite all i did.

Its been two days since i flushed and added potassium and regular feeding back, i think it would've reacted to it already, but i'm open to being corrected.

Maybe its something related to the light?
I mean most of the burned stuff is closer to the middle where the light is, but then also probably most of the plants productivity i'd guess, so it might show deficiencies much more vigorously? doesn't generally look light related as far as i know though.

Got some better pictures might help us out here...

 

[Bongstar420]

Stop flushing if your not too high on EC. Just add the correction and don't add the usual.

The looks of the plant is of little help if we do not know what you have in the nutes and media. According to the labels of the two items you listed, it is highly likely that you are Magnesium deficient. Its common for deficiencies to show first on the fastest growing parts of the plant as you have questionmarked.


For the stage of flower you are in with the mix you stated, its unlikely you are seeing a Potassium deficiency.


I'd say you have about twice the amount of Ca relative to Mg that you want in most cases. You won't want to reduce Ca, but increasing Mg seems to be in order. I'm a little surprised your not seeing N deficiency though as I usually have to put on more N than that formula provides and don't see reduced need till 3/4ths the way through flowering.

Add epsom salt (about 1g per 3ml of your mix- mix separate as they will probably react with Ca dropping out of solution which won't penetrate the media well). Do not flush. That is a waste unless your PPM is pushing 1500. Cut MgSO4 about 2 weeks prior to pull because this stuff will give you fireworks in the bowl. Adjusting now may not help much, but you could at least see if there is rebounding and know for the next round. If you are willing to spring for something fancy, Magnesium citrate from the health food store. You won't have to worry about high S levels from epsom in that case plus its microbe food, chelates, and won't drop Ca when mixing. You would want about 0.8g of Magnesium citrate per 3ml of mix instead of 1g because its got about 20% more Mg by weight. Fortunately Mg deficiency is much more forgiving than a Ca deficiency developmentally wise.

I grow soil with 0 run off and have the same soil going for years (15 cycles now)...only on occasion do I "leach" the media between grows in case of NaCl buildup because I use unfiltered tap that has trace NaCl and also use organics that tend to have more in them than the water.

Humidity in 60% is fine. If it goes higher after mid flower, your risking botrytis though 80% during the dark cycle isn't much of a prob unless its hot.

If your problem was K deficiency, simply skipping the 3-8-8 for a watering or two would fix it without leaching.

I would add micros as that Grotek looks a little lite on em

Thanks for the info guys, i think windy's link provides stronger evidence for potassium deficiency.

Flushing seems to be common practice in soil grows so today i decided to flush even though it was pretty hard with the scrog and everything tied to it.


I flushed 30 liters tap water until the EC of the runoff was 0.4 and then i gave it 3 liters pH 6 water with about half of the feeding she used to take and in addition a potassium additive for this period in flowering.
(2 ml/l Growtek Bloom NPK 3-8-8 and 1 ml/l Growtek heavy bud NPK 1-0-3)

Also a small note, the humidity got a bit higher this week to about 60%, i don't control this but i was wondering whats the effect of this.

I'll keep updating.

 

[DerWizard]

That's really interesting bongstar thanks.

The looks of the plant is of little help if we do not know what you have in the nutes and media. According to the labels of the two items you listed, it is highly likely that you are Magnesium deficient. Its common for deficiencies to show first on the fastest growing parts of the plant as you have questionmarked.

Yeah these two are all i had and all i used until now, i thought its supposed to be pretty complete... (actually its the first time i used heavy bud as well)

I'd say you have about twice the amount of Ca relative to Mg that you want in most cases. You won't want to reduce Ca, but increasing Mg seems to be in order. I'm a little surprised your not seeing N deficiency though as I usually have to put on more N than that formula provides and don't see reduced need till 3/4ths the way through flowering.

I might have generally loaded it with alot of Nitrogen early on, was pretty dark green for quite a while.
But would Mg deficiency cause the burned spots? i have calmag from advanced nutrients but its loaded with Nitrogen i'm afraid to use it at this point of flowering but maybe i should? either that or ill get one of the additives you offered.

Anyway growing with 0 runoff - i've never heard of it, its such a big No No in all guides, but i thought its basically supposed to be quite possible... as well as not fully flushing in a soil grow, i feel its just the simplest solution.

 

[Bongstar420]

The burned spots are probably not burning or they could be Mg deficiency causing some PK burning. Different cultivars will not show the same condition identically. I know it doesn't look a whole like what we are trained to look for with Mg deficiency, but I think its a good bet you are looking a a primary Mg disorder. Unless you pH is something like <5, I would think adding some Mg would be helpful.

You can get 2 lbs of epom salt for like $3-5 from the grocery store. No N in that. Just make sure its not bath salts. I saw epsom salt with lavander added and I do not know if that is cool to put on though I suspect its probably not bad.

0 run off is shunned by all of horticulture. It takes tremendous accuracy and good diagnostic skill to pull off. I've toasted dozens of plants in my days. And I do leach in case of overdosing or after a few cycles when I think NaCl may be getting kind up there. But I am growing old soil now...the base is just bark and perlite. I always aimed for proper balance which IMO make flushing far less needed. I've smoked unflushed stuff that was fertilized a day prior that was as good as any though not what you would consider elite finished.

That's really interesting bongstar thanks.



Yeah these two are all i had and all i used until now, i thought its supposed to be pretty complete... (actually its the first time i used heavy bud as well)



I might have generally loaded it with alot of Nitrogen early on, was pretty dark green for quite a while.
But would Mg deficiency cause the burned spots? i have calmag from advanced nutrients but its loaded with Nitrogen i'm afraid to use it at this point of flowering but maybe i should? either that or ill get one of the additives you offered.

Anyway growing with 0 runoff - i've never heard of it, its such a big No No in all guides, but i thought its basically supposed to be quite possible... as well as not fully flushing in a soil grow, i feel its just the simplest solution.