Strange issue - necrotic stripes on leaves - PH? K def? Mag def? Nutrient burn?

[EasyCheesy]

I think it was simply just a stability issue in the root zone between water, nutrient concentration (as the media dries and plants uptake water nutrients can become more concentrated), nutrient ratios (same deal without frequent feeding and run off)
, ph fluctuations in the media etc.

Ok, thanks. It's weird that it's just popped back up again even though I am watering more frequently now, and it seems worse as I lower the feed ec, hence what made me think it's a deficiency. Hopefully if I keep up the daily watering it'll stop.

 

[Aqua Man]

Ok 1.1 going in but qhats coming out? Tip burn like that is not cause for major concern but more of an indicator. Dark green shiney leaves with tips clawing down and tip burn is nitrogen. Excess calcium can also cause this believe it or not. To add calcium and potassium compete for uptake so thier ratios are important as are all nutrients. I won't get into this but after stretch cut cal mag to half. Ideally calcium doesn't need to be anymore than nitrogen so around 100-150ppm is plenty even when the plants are vigorously growing. Most cal mag calls for double this on the directions. So half dose is about where ya want to be. After stretch can even cut to 1/4 usually without issue.

Potassium demand picks up mid to late flower as N and Ca demands drop. Both can affect K uptake.

So the second last reason you may see tip burn is a K deficiency. It starts usually mid plant and a it progresses it will spread along the edges of the leaves starting to burn the serrations. At that point you know almost for sure its a K deficiency.

light is another cause and will start on the upper most leaves. With K and light tips may start to curl upwards as it progresses.

Now I think this is all cause by fluctuations in the root zone. From concentration to ratio etc. As I posted previously. A flush ir few feeds with high amount of runoff followed by a nutrient dose of probably around 600-800ppm of a balanced nute with half cal mag should help prevent it from progressing.

Lower the light intensity for a few days after and all should be well.

test your runoff to compare what's going in and what's coming out. This is best done with a syringe from the bottom of the pots in the saturation zone if possible but if not just the run off.

can you post the results of that?

Ah ok , my bad

Yeah that makes sense. Do you see multiple deficiencies though? I just see that weird bronzing/browning coming in from the edges of the leaves inwards in between the veins, and a little bit of tip burn.
If I weren't feeding them so lightly (last feed was .9ec, and that's including my base water ec of .6) I'd assume it was just a bit of nutrient burn, in fact I did think that last week, which is why I reduced the feed from 1.1. to .9, but it doesn't seem to have helped.

 

[EasyCheesy]

Ok 1.1 going in but qhats coming out? Tip burn like that is not cause for major concern but more of an indicator. Dark green shiney leaves with tips clawing down and tip burn is nitrogen. Excess calcium can also cause this believe it or not. To add calcium and potassium compete for uptake so thier ratios are important as are all nutrients. I won't get into this but after stretch cut cal mag to half. Ideally calcium doesn't need to be anymore than nitrogen so around 100-150ppm is plenty even when the plants are vigorously growing. Most cal mag calls for double this on the directions. So half dose is about where ya want to be. After stretch can even cut to 1/4 usually without issue.

Potassium demand picks up mid to late flower as N and Ca demands drop. Both can affect K uptake.

So the second last reason you may see tip burn is a K deficiency. It starts usually mid plant and a it progresses it will spread along the edges of the leaves starting to burn the serrations. At that point you know almost for sure its a K deficiency.

light is another cause and will start on the upper most leaves. With K and light tips may start to curl upwards as it progresses.

Now I think this is all cause by fluctuations in the root zone. From concentration to ratio etc. As I posted previously. A flush ir few feeds with high amount of runoff followed by a nutrient dose of probably around 600-800ppm of a balanced nute with half cal mag should help prevent it from progressing.

Lower the light intensity for a few days after and all should be well.

test your runoff to compare what's going in and what's coming out. This is best done with a syringe from the bottom of the pots in the saturation zone if possible but if not just the run off.

can you post the results of that?

Thanks for this. Just watered them at 5.5 pH with 1.1 ec feed. Runoff was around 5.8-6, and ec was around 1.0. Bare in mind their last feed was .9ec, and around 6ph. The runoff pH/ec is typically very close to whatever they were last fed, so I'd be surprised if it's salt build up.

It's been 48hrs since their last water and some of them actually were light this time, so they're definitely drinking faster - I'm gonna make sure they get watered every day now.

Calcium tox is a definite possibility as my water is hard, around 200-250ppm of caco3 according to my water supplier. I'm using hard water nutrients to compensate, but I also started adding a bit of calmag here and there as I wasn't sure if these issues were a calcium def (coco, high powered LED's, hw nutrients - seemed possible).

Is it safe to assume that they will not be calcium deficient, considering the high levels of calcium carbonate in my water?

 

[EasyCheesy]

And to clarify - I don't typically use any calmag as my water is so hard.

 

[ComfortablyNumb]

Did this happen by chance a few days after the last cal-mag supplement?
I'm thinking Magnesium only and its complicated by the additional cal in the water.

 

[EasyCheesy]

Did this happen by chance a few days after the last cal-mag supplement?
I'm thinking Magnesium only and its complicated by the additional cal in the water.

It's very possible... the bottle calls for 1ml/L and I was occasionally adding probably closer to .25ml/L as I knew it was risky. I think I was also adding calmag when it first appeared too... hmm.

I'll cut out the calmag and keep adding the epsoms.

 

[Flexnerb]

Thanks for this. Just watered them at 5.5 pH with 1.1 ec feed. Runoff was around 5.8-6, and ec was around 1.0. Bare in mind their last feed was .9ec, and around 6ph. The runoff pH/ec is typically very close to whatever they were last fed, so I'd be surprised if it's salt build up.

It's been 48hrs since their last water and some of them actually were light this time, so they're definitely drinking faster - I'm gonna make sure they get watered every day now.

Calcium tox is a definite possibility as my water is hard, around 200-250ppm of caco3 according to my water supplier. I'm using hard water nutrients to compensate, but I also started adding a bit of calmag here and there as I wasn't sure if these issues were a calcium def (coco, high powered LED's, hw nutrients - seemed possible).

Is it safe to assume that they will not be calcium deficient, considering the high levels of calcium carbonate in my water?

If i were you id read the write ups that @Aquaman wrote...very infomative im sure....READ THEM! Plz

 

[EasyCheesy]

If i were you id read the write ups that @Aquaman wrote...very infomative im sure....READ THEM! Plz

I have read them, they were helpful. Is there something in the comment your replied to which implies I didn't? I'm sure I could have missed something.

 

[SeedyScene]

I have read them, they were helpful. Is there something in the comment your replied to which implies I didn't? I'm sure I could have missed something.

Hi, for coco growing, I highly recommend this website: https://www.cocoforcannabis.com/
I use it as my main resource for growing in coco. I think it's very accurate. This forum is my other resource for anything else not covered on the cocoforcannabis site.

 

[detroitjoe]

Hi, for coco growing, I highly recommend this website: bla bla bla .com
I use it as my main resource for growing in coco. I think it's very accurate

This forum is my other resource for anything else not covered on the bla bla bla .com site.

uhm..what are we, chop liver??

This is a great thread!

 

[SeedyScene]

Can't tell if you're joking or not. The blah, blah, blah site is dedicated to coco in ways this forum is not. The site allows me to not have to decide whose opinion is the most accurate and go down rabbit holes as a new grower.

Responses like yours are the reason why I love cocoforcannabis.com. I don't have to deal with typical forum crazies, egos, constant contradictory info, etc. In fact, you've convinced me to stop giving money to this forum or using it, but you can keep contributing. Oh, never mind, you don't.