Hey, RIU. Having another leaf problem. Pls have a look and help if you can

Hey. Hope everyone is having a good day. Lovely here in London today.

I got home from work yesterday to find a whole bunch of the big shade leaves on my plant yellowing. At first I thought this might be normal (the plant just using up the nitrogen?) as she's in week 4 of flowering. She is sativa dom (I think - bagseed) so I thought this a bit early but tried not to panic myself. This morning I went to look at her and there are really tiny red spots now on the leaves. I looked up the symptoms and think it looks like either K or an Mn deficiency but really I am a newbie and need help

It's really impossible to photo so let me describe it again: The leaves are turning from their normal green to a lighter green to yellow. There are tiny red spots. Leaves are warping and losing shape some what.

There is some burn spots and tips from previous N overdose (at least that was what I was told on here). Was instructed to just use just water and that's what I've been doing for the last week. Before that I was using Biobizz nutes in tiny quantities at every watering. I pH the water to 6.5 because it comes out as 8.5 where I live

Growing in 75% All Mix 25% regular potting soil. Using CFLS

Thank you........

Just had another look. the red spots spreading quite rapidly but still isolated to large leaves. Happening now to leaves that aren't yellowing which almost makes me think I have two problems.

Do you ph the water before or after nutes are added? maybe your lowering it too much.

I pH the water before. When I first started doing this I tested the pH after adding the nutes as well and it doesn't seem to effect it. Run-off also shows up as 6.5. I am using one of the drop kits with the colour charts. I lower it from blue to yellow. Is this reliable?

Spreading very fast. Reading Jorge Cervantes Growers Bible. Sounds and looks just like Manganese defiency expect it started on the bigger older leaves first. Can anyone help? Have a grow shop round the corner but probably shut now. Can get something in the morning.

Can a mod move this to General Problems?

It could be a nitrogen deficiency. Are the large leaves on the bottom yellowing first, and moving up the plant? Are the stems and petioles red or purple? I would resume normal feeding, but not in tiny quantities, normal amounts along with the adding of calmag to the mix. The plant will need calmag anyway at around this stage in the plants growth, so if your not using it start to. The red dots I'm not sure of what that is besides insects. Have you checked your leaves with a magnifying glass for eggs or the like? Good luck

It is not insects. The red spots progress to brown dead spots on leaf. Looks to be K defeciency and have followed instructions in Jorge Cervantes book

Either you locked it up or you have a multi-nutrient deficiency... what are you using for ferts?? No way to help you 'tweak" if we don't know what you use!!

i dont claim to be an expert but it looks to me like the only leaves that its happening to are the lower, larger leaves which i wouldn be too concerned with if it was me. especially since its bagseed. i would just remove the leaves that are yellowing just incase its a disease or fungus but it may just be the plant putting more "energy" into forming buds instead of shade leaves. but like i said im no expert and as always, stay smokey

Super Subliminal said:

Spreading very fast. Reading Jorge Cervantes Growers Bible. Sounds and looks just like Manganese defiency expect it started on the bigger older leaves first. Can anyone help? Have a grow shop round the corner but probably shut now. Can get something in the morning.

Can a mod move this to General Problems?

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Manganese is an immobile element so it can't be that. I would guess it's a K deficiency too .. I literally had the exact same problem (N toxicity, stopped giving nutes) and ended up with yellowing of the biggest fan leaves, starting at the tips and working inwards with some brown spots. Started giving nutes with lower N and she's looking much better now.

Thank you for all the responses. Here is a pic of what the the leaves looked like this morning. Think it confirms it was K?



I hope so cos here's what I did. I flushed it with x2 the amount I normally feed incase I'd locked it out, and since I don't trust the pH tester and I read yesterday that soil buffers the water itself (???) I didn't pH it (there is so much info out there it can be so confusing). Also I remember when I grew with my dad we never pHed and then I read that thread that's up top at the moment. Then I feed it with Biobizz Bloom (3ml/l) 2l.

she seems absolutely fine and still quite perky from all that water and spreading seems to have stopped. Have I done the right thing?

I've lost probably about 6-7 really big shade leaves

LadyZandra said:

Either you locked it up or you have a multi-nutrient deficiency... what are you using for ferts?? No way to help you 'tweak" if we don't know what you use!!

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I have Biobizz Grow, Bloom and Top Max

I think it`s nutelock, check your pH meter; problem could be in your pH meter.

There are things other than pH that can lock out nutrients. Cold/high temps, over/under watering (doesn't seem to be the problem)...

Check your nutrients first. If you know what all your plant is getting, and you are pretty sure it has everything it needs, then the problem might be somewhere in the environment that's keeping it from being regular.

What is your set up like? A lot of people forget the important light and fresh air play, as well as water when it comes to a plant being able to use its nutrients.

what are you temps? I quit using biobloom because of high P, I just use biogrow instead and everything seems to work out very good for me. Are you adding any cal mag? For me it looks like a regular N def..

Hi again. I grow in a cupboard in the hall of my flat. Using big CFL bulbs. (500w in total). Have no ventilation so leave cupboard door open all day, there is also a skylight above the cupboard. I use two fans to blow the air around. Temps about 80 most of the day. Don't own an electronic pH meter. Think the problems stopped. I'm sure those leaves won't recover but it's looking to have stopped soreading. I think, I hope.....

I'm not really sure if it's getting all the right nutrients it needs. In fact I'm pretty sure it's not cos this is happening. I'm new to nuterients - never used them on previous outdoor grows. I was told last week to stop using the nutes cos one user on here said I had a tiny bit of N burn. That's when the problem started. I think I pHed the water down too much. Don't trust the colour strip and am not pHing water at all now!

Don't have cal mag or even know what it is. Will look it up. Thank you

Super Subliminal said:

Don't have cal mag or even know what it is. Will look it up. Thank you

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cal mag is such a common deficiency especially when you switch to flower. if you'd have something like aptus camg-boost and biobizz biogrow, you could get through the grow without any deficiencies. do not panic about ph, in soil it's a rare thing to have. i leached my plant with 60l of 8.5 ph water and soil still buffered it back to ~7 pH.. when you start seeing leaf problems, first thing you do is check N deficiency, calcium and magnesium and only then start thinking about anything else.
which leaves are yellowing? bittom middle ones? how about top of plants? have any pics? if u have n tox that would appear on top first. quit using biobloom, ime it caused only problems.

Looks like your basic Nitrogen deficiency too me. I would up its Nitrogen and add a bit more Magnesium also.