Interveinal chlorosis on top of the plant

[Aimeone]

Hi guys,

First of all I want to say hi. I’m new to the board and this my first post. Sorry that immediately i need to bother you with my problems, but I figured that here is a lot of knowledge. I’m also sorry that my English is not as well since it’s not my mother language.

I would like you to have a look at my ladies. Seems like they didn’t take the last feeding so well, which was like 5 days ago.

Let me give you some details:

Strain: kali China (ace seeds)
Medium: Plagron light mix(slightly fertilized)
Potsize: 7 l (2 gallons)
Veg. Time: 35 days
Flower time: 16 days
Space: 2 ft x 2 ft
Light: 180 w led (hanspanel), 1 ft distance
Water: 25% tab, 75% destilled water
Nutes: GHE Flora (soft water)

Since I use super low fertilized soil I feed with every watering. I water with 3/4 gallons and raised the ec with every watering. Since I use led and temperature is like 23 degrees Celsius I only need to water once a week.

Last watering was with ec 1,2 and ph 6,5 with the ratio of g-m-b 1-1-1 or n-p-k 8-6-12.
For me it looks like there is maybe an imbalance of K-Ca-Mg which leads to a mag deficiency. The plants only show the symptoms on top part of the plants. Bottom leaves are still fine. I could even imagine there is an excess of potassium since I saw an illustration with similar symptoms, which are for example:
- new leaves grow thin blades
- new leaves develop interveinal chlorosis

The symptoms appeared after last watering.
I would really like to hear about your theory and welcome every hint.

 

[MrSauga]

which leads to a mag deficiency. The plants only show the symptoms on top part of the plants. Bottom leaves are still fine.

Magnesium is a mobile element, so you would see the problem start at the bottom and work it's way up. I notice you are pH'ing at 6.5. I would look at dropping that around 6.2. I believe you can pH between 5.6 and 6.5 with that stuff. Some say no need to pH.
The lights are only a foot away, and yes it's only 180w, but you could be bleaching the leaves if it's the tops only.

 

[Aimeone]

Magnesium is a mobile element, so you would see the problem start at the bottom and work it's way up. I notice you are pH'ing at 6.5. I would look at dropping that around 6.2. I believe you can pH between 5.6 and 6.5 with that stuff. Some say no need to pH.
The lights are only a foot away, and yes it's only 180w, but you could be bleaching the leaves if it's the tops only.

That is what I was thinking as well and which confuses me. So can I totally forget about the Mg topic?
What do you think about my potassium theory based on the attached illustration?
I was already thinking on the paneldistance too. But on the other hand it is dimmed to 75-80% and only two of my showing that symptoms. There is one taller plant even closer to the light not showing anything similar

 

[MrSauga]

That is what I was thinking as well and which confuses me. So can I totally forget about the Mg topic?

Yes, the bottom leaves would have been yellow by now and the tips turned up. Most likely you would have seen brown spots on the older yellowing leaves as well.

What do you think about my potassium theory based on the attached illustration?

Again, K is a mobile element. It Will start at the bottom. Your leaf margins would also be showing brown burns and curling up.
I suspect it's an immobile element that's causing the issue if in fact it's a def. I would have to see the NPK values of all your products and how much you add per gal or 4L. It may help me understand what nutes it may be lacking.

I was already thinking on the paneldistance too. But on the other hand it is dimmed to 75-80% and only two of my showing that symptoms. There is one taller plant even closer to the light not showing anything similar

Ya, I'm not saying it is. Some plants react differently with lights at different heights. Just something to consider.

 

[MrSauga]

I should correct myself on the K problem starting at the bottom. It can start near the top but not as often.

 

[Aimeone]

Yes, the bottom leaves would have been yellow by now and the tips turned up. Most likely you would have seen brown spots on the older yellowing leaves as well.

Again, K is a mobile element. It Will start at the bottom. Your leaf margins would also be showing brown burns and curling up.
I suspect it's an immobile element that's causing the issue if in fact it's a def. I would have to see the NPK values of all your products and how much you add per gal or 4L. It may help me understand what nutes it may be lacking.

Ya, I'm not saying it is. Some plants react differently with lights at different heights. Just something to consider.

I’m using the Flora 3 part series of general hydroponics/ GHE which comes with micro (softwater), grow and bloom. Last time watering I used 6 ml/ 6l of each. So more or less 4 ml of each/ per gallon.

 

[MrSauga]

I’m using the Flora 3 part series of general hydroponics/ GHE which comes with micro (softwater), grow and bloom. Last time watering I used 6 ml/ 6l of each. So more or less 4 ml of each/ per gallon.

OK so if I combine all the nutes(I know which is grow, but it didn't say in the pic which was micro or bloom) you have a combined total NPK of 3-2-4. That makes a NPK ratio of around 12 for arguments sake. Cannabis likes around a 23 ratio of NPK. Your N load is low around 106ppm. Below 90 and you may see yellowing, above 150 and you'll probably get tip burn.
I have to run out for a bit. If you can let me know which is the micro and bloom I can try and adjust your feeding for you if you like. Nothing from the way you are feeding it is locking out any other nutrient. It's not that bad really.
I'm assuming maybe the 0-5-4 is bloom.

with the ratio of g-m-b 1-1-1 or n-p-k 8-6-12.

My numbers vary from those (3-2-4)

 

[Aimeone]

Thank you so much for taking time for me. And yes you are right, the 0-5-4 is the Bloom. Other one is the micro.
About the npk ratio, I got it from a tutorial. My thinking was that you just add all numbers together right?
Well but even then I get to 8-6-11 (not 12)

 

[Emilya Green]

@MrSauga has this well in hand but I want to throw my 2c in...
I agree with the diagnosis and getting the nutes dialed in... but let me clarify about the pH and what it is we are dealing with here. A quick search on the medium gives us this:

PLAGRON

Light Mix soil is composed of the best types of peat, mixed with several fibers and perlite for optimal oxygenation and lightness of the substrate.. The particularity of this soil is that Light Mix contains very few nutrients, allowing the grower to have complete control over the nutrition of his or her marijuana plants by using liquid fertilizers,

Not being a soil at all, the appropriate pH is in the hydro range, and at least in that broad sense, it is important. I would suggest a pH adjustment to 5.8-6.1 to start, with occasional dips to the low end... but that is simply my opinion and how I would do it. I can't back it up with nothin... Do what Sauga says.

 

[bluter]

^ have friends in soilless mixes and that is exactly how they do it. ^

one of them has a recipe for a soilless mix using cheap off the shelf big box store stuff i should get

 

[MrSauga]

About the npk ratio, I got it from a tutorial. My thinking was that you just add all numbers together right?
Well but even then I get to 8-6-11 (not 12)

I multiply the NPK value by the amount used. Then I divide that amount by the overall amount for each element which gives you a ratio. If your N values for all three products were 1, 4, 3 then 4mL * 1 = 4, 4 * 4 = 16, and 4 * 3 = 12 for a total N of 32. That gets divided by the total number of mL which is 12, 4mL for each product. That gives you the total N per feeding. You do that for P and K and break it down into ratios.

@MrSauga has this well in hand but I want to throw my 2c in...
I agree with the diagnosis and getting the nutes dialed in... but let me clarify about the pH and what it is we are dealing with here. A quick search on the medium gives us this:

Not being a soil at all, the appropriate pH is in the hydro range, and at least in that broad sense, it is important. I would suggest a pH adjustment to 5.8-6.1 to start, with occasional dips to the low end... but that is simply my opinion and how I would do it. I can't back it up with nothin... Do what Sauga says.

I agree 420% with the pH. I think I mentioned down to 6.0-6.2 but yours is better yet.

 

[Aimeone]

Thx so far guys. Btw @MrSauga when I was talking about the k topic I wasn’t talking about a deficiency I meant a excess of k. It somehow fits to the illustration don’t you think? But there it also says: medium got acidic.
Hmm. Not sure how to go on. So you guys think I should lower the ph to around 6? Do i need to flush?
Could you suggest a ratio of nutes? And maybe how strong?

Need to say symptoms are not advancing so much or at least not fast

 

[MrSauga]

OK @Aimeone ... it doesn't matter how I configuer those products I can't get you what would be considered ideal. Your N load to me needs to be higher up. I mentioned it was 106 after an initial check but in fact it's 84ppm. Personally to me I would like to see that higher. The only way is to increase all 3 parts. If we change just the one, such as the bloom, the numbers go way off.
If 4L of water, if you increase each to 5mL it goes from 84 to 106. If you increase each to 6mL it goes to 127. I'd recommend either of those regardless of the pH as they are probably looking for more nutrients. Your micro looks like it has all the good stuff to so I don't want to cut that off obviously.

 

[MrSauga]

If your N:K ratio was higher than 1:3 I would agree it was toxicity. But your numbers are so low it's not getting much of anything really. The way you are feeding is fine. I just don't think it's enough.

 

[MrSauga]

No need to flush a healthy plant. Just bring down the pH as Emilya pointed out and I'm sure your problems will disappear.

 

[MrSauga]

Hmm. Not sure how to go on. So you guys think I should lower the ph to around 6? Do i need to flush?
Could you suggest a ratio of nutes? And maybe how strong?

Unless something happened to the medium that we dont know then chances are it's not too acidic. If it's too acidic it would lock out K, not cause a toxicity from my understanding. It's best to work with the obvious first and make small changes before ripping up the whole grow.

 

[Aimeone]

Ok. I’ll give it a try with one plant which is not showing symptoms yet because I just realized the other ones are still to moist. Let’s see how she behaves after watering. I’ll give it a bigger load.
Any suggestions for a good K-Ca-Mg ratio? Since I use the soft water version there is a lot of calcium in the micro. I don’t want to mess that up

 

[MrSauga]

I've been meaning to ask that as well. You are using softened water? I notice earlier you said your EC is 1.2, about 600ppm. What does your water measure before adding nutes? I would have scrapped the micro in your case and used a calmag supplement. Changing the micro messes the grow and bloom values. They have to work together.
To answer the ratio question I would have to do some looking up on that.

 

[Aimeone]

Well. The problem is my tab water because it has high amounts of nitrat, sodium, chlorid and hydrogencarbonat. I fucked up two grows already before I found out. This is why I mix it up with destilled water. It has an ec of around 0.2 before adding nutes. What do you think would be a proper total ec?

 

[MrSauga]

Understood. I use this chart as a reference only.

So take whatever value and divide by 500 to get the EC. Your water is at .2 EC, so your feed is coming in at 1 EC, around 500ppm. Again things point to being on the low end of feeding.