Leaf discoloration about 50 days into flower

[billysnarf]

Need some input guys/ gals.. Unidentified strain 50 days into flower. 400W HPS, coco grow.. Using Botonicare NC17 nutes... bloom, liquid karma.. Added some Cal Mag the day before pic was taken... I was leaning towards nute burn because I upped the PPM about a week before I noticed the discoloration... BUT I think it is some other deficiency.. I had not used any Cal Mag since I transplanted at the beginning of flower.. BTW using PH'd tap water..1 gall smart pot..

 

[al70]

just a guess
Magnesium Deficiency


Problem: The edges of the leaves may become yellow or bright green and may start feeling crispy to the touch. The light green or yellow coloring may also effect the veins of the leaves.

Solution: It is very important to maintain a proper pH in order to avoid a magnesium deficiency. Adding more magnesium to a system when there is a pH lock-out will only make the situation worse because the plant will not be able to absorb any magnesium until the pH has been corrected. Flush the system with properly pH'ed water that contains a full set of proper nutrients and see if the new growth starts looking healthier.,something to look into, goodluck.

 

[billysnarf]

First off, thanks for the fast reply.. If you look at the first pic on the left that I posted.. About half way down the plant.. You see some yellowing in the big fan leaves.. This looks very similar to the magnesium def pics that you posted...This is how it started.. then progressively got worse as the upper fan leaves started discoloring as well... two days before the pic was taken, I flushed w/ ph'd water... then the day after that I added some Cal Mag with a light feeding.. As of now, I cannot tell if it has got any better or worse.. I am going to re-calibrate and make sure my ph is spot on as well..

Should I consider Epsom salt? or would Cal Mag be enough for a magnesium def?

 

[billysnarf]

Follow up. I think you were exactly right.. As it turns out my pH meter was screwed. It was measuring everything 1.35 - 1.4 higher than it actually was.. so when i thought I was at 5.8 the pH was actually around 4.45... Glad I figured this out now.. Learned a lesson.. i thought my meter was spot on.. never trust a meter that has not been calibrated recently.. hope the plant gets better..

 

[BigSteve]

It has to much nutrients with not enough light. It's throwing a bunch of individual leaves with no crystals on them. It looks like it isn't getting enough light. It's 50 days in and there are no buds.

Are you running a vented hood or a 400hps shop light? How far from the light is the plant? Are there other plants and what do they look like? How much nutrients are you giving it? What is the temperature in the room?

 

[billysnarf]

BigSteve- Tell me what you think.. Agreed on the low bud production.. BUT I think the entire time it has been in flower my Ph meter has been off by at least 1.35.. SO assuming the entire 50 days it has been fed with a solution that I thought was 5.6-5.9 BUT was actually 4.25-4.5... Im guessing that this low Ph halted the bud production..

Vented tube ..6-8" from the top of plant...Temps in the room got up to 86-87 daytime during the duration of the 50 days.. 74 at night.. so damn hot here.. my a/c in my 2 story house couldnt even keep up..

I was feeding the plant CNS17:

Bloom 15ml/ gall
Karma 5ml/gal......every 2-3 days.

 

[Femora]

Heya Billysnarf!
Im curious.. Do did you feed them at that low pH, or is that the runoff?

Im feeding my plants at ec 0.7-0.8 @ pH 6, and the runoff comes at 4.3~!!

Ive flushed the plants with 3x medium tapwater at pH 6.1 and still I wont get my runoff to be just more then 4.5-4.6.. but my runoff ec is 0,05 higher then what I water with..
I really dunno what I should do next. I wont get any response in my thread so now Im around in threads looking for answers..

Best of luck mate!
Fem~

 

[al70]

Managing pH in my cannabis grow: How to check and adjust the pH of water


--------------------------------------------------------------------------------




Why is pH important when growing marijuana?

It all has to do with nutrients. Different nutrients get absorbed at different pH ranges.

You see, he pH of your marijuana plant's root zone is very important to preventing nutrient problems with growing marijuana. This is because when the pH is too high or too low, the plant's roots will not be able to absorb nutrients properly.

Take me straight to the marijuana root pH Charts!
Soil pH Chart
Hydro pH Chart

As a result of the pH being too high or too low, cannabis plants may start showing signs of nutrition deficiencies even if the nutrients are available in the growing medium.

Glistening trichomes on Northern Lights buds - most growers need to check pH to grow buds this happy

Yes, that's worth repeating. You will prevent nutrient problems by checking and adjusting your pH in your marijuana grow.

In fact, feeding your plant with the incorrect pH is one of the most common reasons that plants develop a cannabis nutrient deficiency. At least when growers write in to us, incorrect pH is the cause of a nutrient deficienty at least half of the time.

So if you want to see glistening trichomes on your marijuana, like the picture to the right, make sure you check and adjust the pH of your water and marijuana root zone.

How to Test the pH of your Root Zone

You can test the pH of a water sample using a pH Kit or a pH Meter. If growing your weed in water, take a sample of the water and then test the pH of your sample .

If your weed is growing in soil or another sort of medium, the easiest way to get a ball-park figure of the root pH is to test the water going into the plant as well as the water that runs out of the bottom.

You can assume that the pH of the water that runs out the bottom of your plant is about halfway between the pH of the water you put in and of the pH of the root zone.

So for example, if you water your plants with water that has been pH'ed to 6.0, and the water that comes out the bottom has a pH of 6.5, you can assume the pH of your root zone must be around 7.0, because the water that came out was 6.5, which is halfway between 6.0 and 7.0.

When trying to adjust the pH of your root zone, make sure to do all changes slowly. It is actually worse for your plant to have the pH change drastically than it is for the plant to have roots in the wrong pH.

Adjust the pH of your Water to Correct Root pH

You will need to add all of your nutrients to your water first before checking and adjusting the pH. Your nutrients will affect the pH of your water so it's important they get added before making any adjustments.

It's a good idea to let the pH cover a range instead of always adjusting to the exact same pH number. Some nutrients are better absorbed at slightly higher pH readings, while others are absorbed better at lower pH readings.

If your marijuana plant roots are experiencing the wrong pH, the most important thing to remember is to make all pH changes to the root zone slowly (never more than 0.5 points in a day) because rapid changes will hurt the plant much worse than being at the wrong pH.

For soil an optimum root zone pH is between 6.0 and 7.0, with the most time spent with a pH between 6.5 - 7.0.

Growing marijuana in soil pH Chart

For hydroponics an optimum root zone pH is between 5.5 and 6.5. With hydroponics, it's especially important to allow the pH to range slightly, as some nutrients can only be absorbed at higher or lower pH's.

Growing marijuana in hydroponics pH Chart (including soilless mixes that include coco coir, vermiculite, perlite etc)

The thing to remember with pH is that you don't need to be exact. What you do need is to be consistent in keeping the pH from creeping too high or too low in your plant root zone.... hope this helps guys,,goodluck.

 

[billysnarf]

Good read al70... Thanks..

@Fem - That was the pH that i put in. I have not been checking the pH of the runoff. I have been mixing my nutes, then adjusting the pH down to what i thought was around 5.8.. BUT in my case, my pH meter was messed up..

Next time I feed I will measure the runoff pH as well.

 

[billysnarf]

Next time i will try and concentrate on the pH of the root zone.

 

[BigSteve]

Were you adding PH down to get the PH that low? I've found that if you use tap water, all base nutrients end up with a corrent PH. And adjusting the PH messes up the plants. This is just in my experience.

Having the PH really low will make them grow funky. 4.5 and lower is pretty crazy. I've had a similar problem, my plants didn't stunt, they got HUGE and stupid. Tons of single leaves coming out of the buds with long stems between each node. Instead of fanning out and stacking. It was like the plant was making 90% stem and 10% flowers. Was wacky. Anyways, just in my experience. I'm not sure my PH got below 4.5 though that's pretty far out.

I just looked at the pictures again and it's probably not as bad as I remembered it in my mind. I think that your main issue is the heat now, but you already know that!

And if you are bored, you should check my journal and recent albums! Nobody ever wants to see my ladies or leave me any messages!

 

[billysnarf]

@BigSteve... Because I was off on the pH meter, it was measuring everything at 1.4 higher than the actual pH so I was adding 3-4 ml of white vinegar (a large amount) to lower the pH. So last night I mixed up a gallon of nutes.....and Steve, you are right... With my tap water and my nutes the solution was already down to 6.1... This time I only had to add .1-.2ml of my ph down(white vinegar) to get it down to 5.8... which this is the way it should have been the duration of flower... I have been adding way to much down bc of my inaccurate pH meter... DOH!

Now it is finally not 104* degrees out, rather low 90's outside.. so the temp in my room is coming down to better temps during the day.. Next summer i will have to find some kind of supplemental a/c for that room..

BTW Steve I have 6 other plants 1.5 weeks into flower in that tent as well.. so far they look ok.

 

[Femora]

al70, Thanks.
My conditions are as following:
I grow in 7-8liter 50/50 coco/perlite. Reused 1 time, and I had low ph issues in my last grow... I gave it a GOOD flush but I still wont get the runoff to be okay. I would like it to atleast hit 5. (5.5 in medum, according to you post)
6 -> 4.3 = 5.15~

I haven´t really understood how the water is getting stabilized...
Like.. if the water is not "stable" you can lower the pH from say 6.4 to 5.5, but 2 hours later is the water reading 6.4 again..

Im thinking that this might have something to do with my pH not going up. Maybe I need some other coco-specifyed nutes that "fill up" the water to make it stable(??) Im really confused in the matter, and if someone could exclude my theory on the subject id be happy with it. Or even better explain to me whats going on and how it works in a easy way.
I just wont get those advanced posts i find about the subject since there is so many words I dont understand I drop the red line in it.
So, imagine that you'd explain it to a 6 year old, LOL!
The question would be;
Whats the different between canna-specified nutes compared to soil, or "pure hydronutes" beside different amounts of all the NPKCaMg.... to maximize it to the growconditions.
Is there some sort of ingredient that is especially good for coco? And Why?

On a side, why is coco so sensitive to recirculating systems??




Billysnarf; I will be curiously waiting for those results of yours!

 

[Femora]

Ow, alot happened since I pressed replybutton..

Were you adding PH down to get the PH that low? I've found that if you use tap water, all base nutrients end up with a corrent PH. And adjusting the PH messes up the plants. This is just in my experience.

Having the PH really low will make them grow funky. 4.5 and lower is pretty crazy. I've had a similar problem, my plants didn't stunt, they got HUGE and stupid. Tons of single leaves coming out of the buds with long stems between each node. Instead of fanning out and stacking. It was like the plant was making 90% stem and 10% flowers. Was wacky. Anyways, just in my experience. I'm not sure my PH got below 4.5 though that's pretty far out.

I just looked at the pictures again and it's probably not as bad as I remembered it in my mind. I think that your main issue is the heat now, but you already know that!

And if you are bored, you should check my journal and recent albums! Nobody ever wants to see my ladies or leave me any messages!

LOL!
Thats exactly how my Outlaw and Euforia were growing in this last run!!

Especiallt the Outlaws looked REALLY funky!

(recirc coco dripfeed. A massive FAIL-mine I had to step on cus I was ignorant and naive to listen to others (I just couldnt understand how it worked, so I had to test it..)


btw, Ill check out your ladies and logs right away!
You might want to concider to put a link in your forum signature to make em easier to find.

Fem~

 

[billysnarf]

Fem - what nutes are you currently using?

Agreed if you put in pH 6.0 and it comes out at 4.3, this would mean the medium is around 5.15? still a tad on the low side.. What problems are you seeing in your grow? anything specific? Or is everything looking good, you are just trying to figure out why you cannot get the pH of the medium up to at least 5.5?

 

[billysnarf]

Ow, alot happened since I pressed replybutton..





LOL!
Thats exactly how my Outlaw and Euforia were growing in this last run!!

Especiallt the Outlaws looked REALLY funky!

(recirc coco dripfeed. A massive FAIL-mine I had to step on cus I was ignorant and naive to listen to others (I just couldnt understand how it worked, so I had to test it..)


btw, Ill check out your ladies and logs right away!
You might want to concider to put a link in your forum signature to make em easier to find.

Fem~

Oh I see now--- you having some FUNKY shit happening too.

 

[Femora]

I have some troubles with the grow.. ya..

They have rustspots on a few leafs showing Phosphorous and Ca I think.
It would make sense with their lockout-range when the pH is that low (i just noticed..)

I can snap some pics, but not before monday or so..

Nutes is;
Green-house power feeding.

http://www.powderfeeding.ch/store/long-flowering-1-kg-bag.html

http://www.powderfeeding.ch/store/hybrids-1-kg-bag.html

Those are the two I work with right now.

 

[Femora]

For what its worth; Ive re-flushed the ladies after transplant. I have 7-10 days veg until flower..
The tapwater is ph 6 @ 0.05 EC
runoff is 4.3-4.5 @ 0.15

Ill keep you updated if it solves my problem, and that would somewhat mean that my previous flush wasn't sufficient..
Well, if you wish to know, that is...

Keep your fingers crossed for my sake. Dunno if its acctually usefull for the OP.

Stay safe!

ps. I snapped some pics with my phone, but I cant upload them from where I am right now. Ill get em up later, with their progress from this flush.. ds.