Yellowing in flower

lukedaduke · Aug 21, 2019

its iron chlorosis. I have no idea what the ppms are in any of the nutrients you are using but they dont have enough iron to support the plants during their stretching period. I use a chelated iron source so I dont have to push my pH down when I flip my plants, but perhaps that what you can do as iron is much more soluble at lower pH ranges (sub 6, dont go crazy haha). Other than that go get a chelated iron supplement and that will fix your issue with in 48 hours. I personally like sprint 138, because if I fuck up and my pH is off i just want to fix the problem then and there, but sprint 330 is cheaper and should work just as well so long as your pH isnt too messed up.

once your plants are thru the stretch period the chlorosis should go away, but they will be somewhat stunted compared to if they had enough iron in the first place.

reggie1387 · Aug 22, 2019

lukedaduke said:
its iron chlorosis. I have no idea what the ppms are in any of the nutrients you are using but they dont have enough iron to support the plants during their stretching period. I use a chelated iron source so I dont have to push my pH down when I flip my plants, but perhaps that what you can do as iron is much more soluble at lower pH ranges (sub 6, dont go crazy haha). Other than that go get a chelated iron supplement and that will fix your issue with in 48 hours. I personally like sprint 138, because if I fuck up and my pH is off i just want to fix the problem then and there, but sprint 330 is cheaper and should work just as well so long as your pH isnt too messed up.

once your plants are thru the stretch period the chlorosis should go away, but they will be somewhat stunted compared to if they had enough iron in the first place.

Awesome reply mate thanks. I’m at work tonight but I’ll try to get some iron tomorrow. The trace elements I have has iron in it? I got GH micro and bloom in the mail today I might go back to the heads formula 6/9 like I use to use before the maxibloom. I didn’t have any dramas before the change e

lukedaduke · Aug 22, 2019

reggie1387 said:
Awesome reply mate thanks. I’m at work tonight but I’ll try to get some iron tomorrow. The trace elements I have has iron in it? I got GH micro and bloom in the mail today I might go back to the heads formula 6/9 like I use to use before the maxibloom. I didn’t have any dramas before the change e

Yep that does have iron in it, not sure if its chelated or not. But its got so many other secondary macro and micro nutrients in it, that I wouldn't feel safe telling you to correct your iron def with that product.

If you are able to get your hands on a solely iron containing product (like sprint) I would suggest a feed with 15 to 20 ppm iron to correct the issues you are seeing. dont go over board, iron toxicity is a thing.

and yeah maybe its a good idea to switch back. Again im not familiar with those products, but having a chelated iron source on hand is never a bad idea because if all of your conditions are right (which they look like they are) your growth during the stretch phase will be down right scary and a normal iron source might just not be enough to keep up with the demand of the plant. So having that option to boost your iron ppms on a whim with out worrying about adsorption rates is such a useful tool, at least in my opinion.

As a side note (and i know im rambling at this point lol) I like to switch to a fertilizer containing higher amounts of ammoniacal nitrogen after the first few days in flower to help drop my pH down a bit to help with that iron solubility idea that I was talking about in the last post. I find that helps a lot with avoiding iron def in those heavy stretch days, but that just my experience. .

Good luck

Luke

reggie1387 · Aug 22, 2019

lukedaduke said:
Yep that does have iron in it, not sure if its chelated or not. But its got so many other secondary macro and micro nutrients in it, that I wouldn't feel safe telling you to correct your iron def with that product.

If you are able to get your hands on a solely iron containing product (like sprint) I would suggest a feed with 15 to 20 ppm iron to correct the issues you are seeing. dont go over board, iron toxicity is a thing.

and yeah maybe its a good idea to switch back. Again im not familiar with those products, but having a chelated iron source on hand is never a bad idea because if all of your conditions are right (which they look like they are) your growth during the stretch phase will be down right scary and a normal iron source might just not be enough to keep up with the demand of the plant. So having that option to boost your iron ppms on a whim with out worrying about adsorption rates is such a useful tool, at least in my opinion.

As a side note (and i know im rambling at this point lol) I like to switch to a fertilizer containing higher amounts of ammoniacal nitrogen after the first few days in flower to help drop my pH down a bit to help with that iron solubility idea that I was talking about in the last post. I find that helps a lot with avoiding iron def in those heavy stretch days, but that just my experience. .

Good luck

Luke

Thanks for the reply mate. I live in Australia I don’t know if we have sprint. Looking on my local hardware shop they sell these products
https://www.bunnings.com.au/manutec-300g-iron-chelate_p2961520
And
https://www.bunnings.com.au/yates-500ml-iron-chelate-leaf-greener-liquid_p2961859

How do you think they will work? I used general Hydroponics flora series before and didn’t have any dramas. So I’ll go back to that I think. This is the plants this morning

reggie1387 · Aug 23, 2019

@lukedaduke i ended up getting this chelate iron

I had 1L spray bottle with water added 10ml. Gave they plants a good spraying with the lights off today around 1230pm. Lights will come on at 8pm so I’ll check then. I dumped my reservoir and and refilled it. I went back to feeding them GH micro/bloom 6/9.
55L of water
40ml calimagic
84ml micro
125ml bloom
Ph 5.9-6.0 EC 1.7
I emptied 15L water and replace with 15L tap water. .5ml PH down. PH 5.8 EC 1.4
Is this ok?

lukedaduke · Aug 25, 2019

Im sorry i didn't respond sooner I was camping in the white mountains this weekend and had no access to the internet!

That chelated iron supplement looks good to me. 1.25% is on the low end but that will ensure that you cant give them a toxic amount by accident.

So you did a foliar feed with the iron then? Nothing wrong with that, so long as it doesn't burn the foliage. In fact that should help to alleviate the deficiency faster than feeding through the roots, great idea on your part really. However, I might suggest also feeding that iron through the roots until the yellowing subsides as they cant adsorb a whole lot through the leaves compared to the root system.

I think those pH's look good, honestly I have very little hands on experience with DWC, I have read about it but only ever toyed with it at home. All of my commercial cannabis experience is in peat, coco and rockwool, so thats the stuff I know like the back of my hand.

So from that experience I can say that I run rockwool at 5.6-5.8 pH and have good success. Rockwool is hydroponics so I think that same range would work for your case, and in fact I have heard of home growers (so take it with a grain of salt because these ones talk a lot lol) say they have done really well at 5.8 in DWC.

I think if your pH range is correct (so 5.8ish) Your EC is at 1.4-1.7 and you are giving them 15-20 PPM iron (remember thats the corrective PPM dont run that longer than necessary) you should be able to get those things greened up and ready to go with in a day or two.

Let me know how it goes, and again im sorry for not getting back to you till now.

reggie1387 · Aug 26, 2019

That’s ok. I ended up giving them 2x foliar feeds with the iron and a calmag Feed. They are looking better. I also lifted my light up. I’ll try adding some iron into my reservoir aswell.

My plants are in coco, 5gal fabric pots. Automated watering system DTW setup the black tub under the plants is to catch my waste run off cause I work shift work and can’t get to them everyday.

I’ll try to get some new photos when I’m off. I actually found out on the weekend my plant was behind in growth after flipping. My tent sits in my shed under a light. The light is only on if I need to find something in the shed. And my tent isn’t as light proof as I thought. It had a few pin hole but the light would penetrate the sides. Had to do some covering (rubber back curtains from the shed) lol

reggie1387 · Aug 28, 2019

lukedaduke said:
Im sorry i didn't respond sooner I was camping in the white mountains this weekend and had no access to the internet!

That chelated iron supplement looks good to me. 1.25% is on the low end but that will ensure that you cant give them a toxic amount by accident.

So you did a foliar feed with the iron then? Nothing wrong with that, so long as it doesn't burn the foliage. In fact that should help to alleviate the deficiency faster than feeding through the roots, great idea on your part really. However, I might suggest also feeding that iron through the roots until the yellowing subsides as they cant adsorb a whole lot through the leaves compared to the root system.

I think those pH's look good, honestly I have very little hands on experience with DWC, I have read about it but only ever toyed with it at home. All of my commercial cannabis experience is in peat, coco and rockwool, so thats the stuff I know like the back of my hand.

So from that experience I can say that I run rockwool at 5.6-5.8 pH and have good success. Rockwool is hydroponics so I think that same range would work for your case, and in fact I have heard of home growers (so take it with a grain of salt because these ones talk a lot lol) say they have done really well at 5.8 in DWC.

I think if your pH range is correct (so 5.8ish) Your EC is at 1.4-1.7 and you are giving them 15-20 PPM iron (remember thats the corrective PPM dont run that longer than necessary) you should be able to get those things greened up and ready to go with in a day or two.

Let me know how it goes, and again im sorry for not getting back to you till now.

So I checked my plants today after changing back the GH micro/bloom, lifted the lights a few inches more, gave them a iron foliar and calmag foliar feed, and covered my tent properly. They look much better. Some leaves are still yellowing tho. Not sure if it’s old damage or new.

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Yellowing in flower

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