Anyone knows what this would be??

Hi got two autos, they r in the 9th week counting from the seedling, they’ve been flowering for about three weeks. I under-watered them once. They in canna terra plus soil. Btw soils been too hot for them since the very beginning, they had burnt tips in late veg even tho I had good temperature, good light distance and I wasn’t using any nutrients at the time. I fed them for the first time week ago with canna flo and cal mag agent, half of recommended dosage. They’ve got some weird spots on the leaves and don’t know but just don’t look too good. I can’t figure out what it might be, see pics below:

plant 1:

And plant 2:

That looks like calcium deficiency. Did it always show with the newest leafs?

That is usually caused by low transpiration. But in combination with burnt tips it could also be lock out. Too many cation (K, Mg and Ca) compete for uptake and if the balance is not right calcium does not get taken up in sufficient amounts and is deficient in leaves, even with enough available in the root zone.

Lou66 said:

That looks like calcium deficiency. Did it always show with the newest leafs?

That is usually caused by low transpiration. But in combination with burnt tips it could also be lock out. Too many cation (K, Mg and Ca) compete for uptake and if the balance is not right calcium does not get taken up in sufficient amounts and is deficient in leaves, even with enough available in the root zone.

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I was thinking that it might be cal deficiency just thinking how to fix it cus as you said it might as well be lockout. I should be watering them tomorrow so I’ll check runoff ph. Do you recon I should flush them with plain water and then add CalMag with the next watering or flush them with CalMag water ?

ReggieDobson said:

I was thinking that it might be cal deficiency just thinking how to fix it cus as you said it might as well be lockout. I should be watering them tomorrow so I’ll check runoff ph. Do you recon I should flush them with plain water and then add CalMag with the next watering or flush them with CalMag water ?

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Maybe? I would first finish the diagnosis.
Where did it first start? New or old leaves.
What were your temps and humidity? Did you have airflow?
Having burnt tips in late veg, when they can take a lot of nutrients, sounds strange after the soil has not been fertilized for 6 weeks.

But someone with more soil experience can chime in.

ReggieDobson said:

I was thinking that it might be cal deficiency just thinking how to fix it cus as you said it might as well be lockout. I should be watering them tomorrow so I’ll check runoff ph. Do you recon I should flush them with plain water and then add CalMag with the next watering or flush them with CalMag water ?

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well you dont have a overfeeding soo you should just add calmag to regular feeding

Lou66 said:

Maybe? I would first finish the diagnosis.
Where did it first start? New or old leaves.
What were your temps and humidity? Did you have airflow?
Having burnt tips in late veg, when they can take a lot of nutrients, sounds strange after the soil has not been fertilized for 6 weeks.

But someone with more soil experience can chime in.

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I think it’s because the soil I use is too hot for autos that’s why they had burnt tips in late veg. Not sure how longs this been going for. On one of them no longer than a week. The other plant not sure as it is in worse state. Humidity 50-60, good airflow temps 20C when lights off 25-26C with the lights on. Good airflow.

amneziaHaze said:

well you dont have a overfeeding soo you should just add calmag to regular feeding

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Should I flush it first as I’m not sure if there isn’t any lockout ?

ReggieDobson said:

I think it’s because the soil I use is too hot for autos that’s why they had burnt tips in late veg. Not sure how longs this been going for. On one of them no longer than a week. The other plant not sure as it is in worse state. Humidity 50-60, good airflow temps 20C when lights off 25-26C with the lights on. Good airflow.

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soo you have too hot of a soil thats why the seedlings didnt have problems whole veg no problem but late veg then the hotness activated?
i feel like you just want to flush.
give her cal mag not too much and dont expect your leafs to get better.remember what leafs where damaged or cut tips from each one of them just enough soo they are different.that way you can see when new leafs start showing same problems then you can give more food