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Completely yellow l...
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Sick Plant Completely yellow leaves

14 Posts
8 Users
Topic starter

Hey Team!! Hope all is well.

I'm around 4 weeks into flowering and im having some issues, my plant has turned almost completely yellow and now another is begging to look pale too.

Didnt have this issue in last run but i've changed alot. There's a couple of things i think it might be

1. New lights I've got around 700w of light in there, a mars hydro tsw200 and 2 200w quantum boards - they are at around 40cm away from canopy though - could they be light bleached? Im not sure this is the problem as is only 1 of 4 plants thats really bad

2. PH - I read that i should use between 5.8-6.2 for canna soil so have been in that range but am now thinking its been too low? The whole leave is yellow but growing fine. Not intravenous, veins are also yellow. The whole plant is this colour, some new growth comes through green but goes yellow quickly. 

3. PK - I've been using some monsterbloom PH 0-50-30 in small doses. I read in eds book that if you do this yo

u can over work th plant as it doesnt have enough nitrogen to manage this but Problem is that plans still seems to be growing ok and lower leaves are not falling off so not nitrogen

Any help would be amazing, im worried im gonna lose her after all this work!


Thanks : )

Screen Shot 2021 11 09 at 9.31.53 PM

Pic of yellow plant next to single cola micro grow of normal colour


Woolie Woolie November 9, 2021 8:45 am

Calmag ? pretty sure its required in a soil grow , Led init , i think coco me 😉 

SouthSilly SouthSilly November 9, 2021 7:56 pm

looks like there is also purpling of stems? 


SouthSilly SouthSilly November 9, 2021 8:00 pm

may I ask where you are growing? is the floor cold? 

10 Answers

For soil I’d try keep the Ph between 6.4-6.8, Think the Coco lads prefer around 5.8-6.2


I think Woolie will be right about needing calmag, I never used calmag for my first few grows because I thought it was only coco growers that needed it.

But I think around mid flower is the time they need calmag most, If I remember correctly it was about 1-2 ml of calmag (in 1L of water/feed) I used each feed In my last run when they turned

In the corridors of power where the talks are in full swing
If you can't say it with flowers Then don't say anything


Ok mate a few things I notice:

Posted by: @noxxy

they are at around 40cm away from canopy though

Thats a bit too close i think mate, all those lights add up, try getting them about 45cm (18-20 inches) from the canopy.

Posted by: @noxxy

5.8-6.2 for canna soil

No mate this is incorrect. Canna coco is 5.8-6.2, as that is a hydroponics medium. If you're growing in Canna soil, it prefers 6.5 - 7.5 pH. Check the back, if it says "Canna Terra" on it, it is soil, if it says "Canna Coco professional +" its coco. Let me know what you have so we can get that right Smile

Posted by: @noxxy

doesnt have enough nitrogen to manage

Nitrogen def will stat from the bottom leaves and work thier way up. From this picture it looks like its mainly on the top of the plant?

If you are in soil, and you have been using hydro pH, then this will be the cause of the problems mate. Let me know what medium youre in, what youre feeding the plant and how much per litre, and also get a couple of pics of the whole plant, so we can see where the leaves are most effected. 

We can get you on track then Smile


"Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great.”
― Mark Twain


I use canna professional soil and the canna nutrient range and I use the cal mag at 1.5ml per litre for the last two weeks of veg and then for six weeks into veg. 

you might also try testing the ph of your feed before and then measure the run off to see if there’s a big swing, hope this helps brother. 


Topic starter

Thanks so much for taking the time to read my post and respond everyone, i really appreciate it!

@Woolie - Thanks mate, i've got CMX from flairform which i havent really added but will do that next time i reckon 👍 

@Southsilly - Yes mate, there is purpling of the stem, is that an issue? I thought that was normal but im still learning, they're Bruce banner clones. They are in a bassment like area, the tent is on polythene on the earth so the ground will be cold but enviro is toasty, around 25c. What you thinkin mate? Those questions have got my interest haha

@Stootie - Im in soil mate, never needed it last run in soil so wasnt sure when to use, good to hear it worked for you when your ones went yellow tho mate, gives me hope lol!

@Rufio - I dont know why i even did it mate to be honest, i read somewhere canna needed 5.8-6-2 but never even thought it might be coco, will adjust the PH next run 😎 i knew it didnt seem right

@Macky - Thanks mate! I am seeing some curling on the leaves so will move them up, its hard to judge as i got them second hand wit no guide so appreciate the advice

 Its soil i've got mate - i had no idea i could go as high as 7.5 i thought 6.8 was the absolute top. Up to now they've been getting nothing higher than 6.4 - what would u recommend i do mate?

I've been feeding them Canna Flora at about 20ml in 9litre - it says put 50ml in 10l but started seeing tip burn at about 20ml. They were drinking but have slowed right down over the past few days

@Fweetch - Had no idea i needed the calmag this much, thats pretty much the same soil and nutes as me, what PH do you give them brother? Good idea to test the run off, i've never done that. Might give this a go and see what numbers it gives me. I do have one of they pens that measures ppm but i've no idea whats going on with it lol.


Thanks so much again everyone, awesome to have this support ❤️ ❤️ 


PS. She's due a feed tomorrow so will have her out the tent and can get some good pics



Get a small mister bottle one that fits in palm of your hand smaller the better

Make quarter strength bloom feed and only spray the underside of the big fan leaves that are away from buds 

Cover the closest bud with a loose baggie to protect from mist 

Do one leaf at a time to be careful not to get mist on buds

Your in soil so any rectification of deficiency can take longer, by spraying the underside of leaves your getting the feed in direct to the leaf

Your low ph may have killed of some micro life, so add back microbes to rootzone 


I never grow a plant, it grows me.

Posted by: @noxxy

 Its soil i've got mate - i had no idea i could go as high as 7.5 i thought 6.8 was the absolute top

This is your problem then mate. pH is off and the plant cant get what it needs from the soil. 

Give them a good watering with water ph'ed at 7.0

Use the same amount of nuits as you have been using now, give it a few dyas and see how the plants look. There still might be plenty of cal/mag in the soil, but the pH has been off so might not have been used. SO dont add any more of that right now. Instead, get the pH correct and see how the plant feels then Smile

"Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great.”
― Mark Twain


Hey mate,  just something to be mindful of. Im also in a basement and if i dont insulate underneath the plant, the cold floor sucks the heat out of the pots and they end up looking like this. I use living soil and everything relies on a healthy active root zone. Not saying its your issue, but it can definitely also cause these symptoms, just know that not all deficiencies are caused by deficiencies overall... Any other issues presenting now? Like any spots large or small?

Posted by: @noxxy

what PH do you give them brother?

I usually keep it around 6 to 6.5 on the bottom of the canna feeding schedule it does tell you to keep them between 5.8 and 6.2 but I haven’t had any issues once I realised you ph the water after adding the nutes🙈😂


Topic starter
Screen Shot 2021 11 18 at 9.51.47 PM
Screen Shot 2021 11 18 at 9.52.13 PM

Hello Everyone!

Sorry this took a few days, had heaps going on.

So i did as @Macky suggested and fed hetr at 7.0 PH with normal nutes. That was around 3 days ago and she's due a feed again tomorrow. Not much change in colour yet but the buds started to fatten out and still no majorly adverse signs. I did check the PH of runoff after giver her a good 10litre and it was at 5.9


Any ideas? Should i just keep giving her the higher PH'd water and hopefully she'll come right?


Thanks all : )


Macky Macky November 18, 2021 1:30 pm

Feed with water at 7.5 if you can mate, but no higher, itll balance things out over a few feeds. Takes a while for things to get back to the right balance in soil. Just give it time Smile

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