Yellowing leaves during flower HELP

Hi guys.

I’m stuck atm. I have some super lemon haze that on flower that I’m having trouble with.

Im on week 5 and for the past 2 weeks they have been going really yellow.

I checked my run off a few weeks back and it was ph was way off (4.9-5.1) which By research is causing the plant not to absorb nitrogen and too much nutes (EC was 3.5)

I’ve been just watering since as the EC was still off1.5-2.0

I’ve added some worm casting to see if it would help the microbe life and kept on watering with ph water.

I managed to get my ph to 5.5 by running water straight from the tap.

I’m stuck as they are still yellowing heaps but I don’t know why haha. They are fattening more and more every day so not sure what to do. If I should keep just with water for a bit longer or start feeding again

Growing some ILGM super lemon haze

Coco coir with 30% perlite


40% RH

Spider farmer sf2000


Green planet 3 part feed + vitathrive + calmag and sometimes I give them some epsom salt

1.2x1.2x2 grow tent

Suspect nute lockout. EC of 1.5 to 2.0 is not that bad, but could be slightly higher.

Unsulphured molasses is a better feed for microbes.


Im watering one of them as we speak and the EC is at 1.5. Should I flush it again? I had it down to 0.9 last flush on this particular one and the yellowing reduced drastically but the leaves are still light green and bottom leaves turning yellow.

I thought about flushing until I get almost nothing on my Ec meter and add nutes. (Not sure if it’s possible or a good idea)

What soil are you using?

Im using coco

Okay. Coco can be a little different and I have no experience with it. My suggestions were for a soil grow. Let’s get someone like @Myfriendis410 to help you. He’s an experienced coco grower. He should be on here in a few hours.

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Two coco coir grows using Jack’s.
A runoff pH of 5.1 is really low. I had to deal with it two times recently. In one case I did not react fast enough or as aggressively as I should have. This resulted in me having to harvest the plant several weeks earlier than what it would otherwise have been

In the second case my plants were showing similar characteristics as the first plant. I was not going to have the same thing happen to these. On day 43 of flower I flushed and flushed again. Got runoff ppm down to 300. Fed immediately with pH at 5.8 and calmag.
They finished normally and resulted in a nice harvest on flower day 84

I would flush them thoroughly and feed them at 5.8 to 6.0 pH with calmag. There severely damaged leaves will not recover. Hope there will be some new growth and for the buds to develop further. Good luck


I’m happy to know it can be fixed.

When you fed them you just added calmag and nothing else?

I’ll get that done tomorrow and let you guys know how it went.

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Looks to me like a N deficiency but I’m not a coco so I really don’t know what you need to do to fix it or if it’s a lack of nutrients or a lockout… ph sounds ok but again I’m no coco, watering is different with coco too if you let it dry can cause some issues…

Having the ph of your root zone so low threw your plants out of whack for a little while. Coco needs to be watered daily and if you let it dry out too much it becomes hydrophobic and can really throw things off.


Oh that’s interesting bc most places I see say that I should water when dry. It would make a lot more sense to water constantly as coco is considered hydro.

I’ll change my watering schedule. I believe my mistake was also not to water till run off most of the time. It’s my second grow (first with photos) my first grow was pretty smooth but I was watering more regularly.


That’s true for soil grows. Coco is a different animal and should be treated more like hydro

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You can even water/feed coco multiple times per day. You should also be feeding with every water too in coco. Just make sure the ppm and ph is correct for the stage your plant is at

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I use Jack’s 321 so gave regular dose of Jacks with calmag in it.

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I use Jacks 321 as well and I never have to add calmag. The line has enough in it already


You are 100% changing my perspective on coco. I’ll definitely change my watering schedule. I’m using green planet GP3 and adding cal mag. I’m in Australia and we don’t have a big selection of nutes

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Nutrient line isn’t as big of a deal as long as the line has enough of everything in it. I understand some places won’t have the same soil, nutes, etc.
Let me know if I can help further. All I grow in now is coco and I feel it is far superior to soil


What he said. Loving coco so much more than soil. It is a pain to have to water everyday but it gives me a re ason to go in there everyday now. Lol. Good luck hope u get it back on track if not and thatll be a small if not. There is always next time.


Now that I am on my third grow using Jack’s I have put my bottle of calmag away except for giving the coco a shot along with a full dose of Jack’s when hydrating it.
Two clones right after transplanting to 5-gallon bags


That’s the recipe! They look happy @beardless :call_me_hand:t3:

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