weird deficiency

[steve870]

Hi,
This is my second grow, i am growing in coco Multifeeding ec@ 1.06 and ph 5.8 to 6.2. Calmag+ 20-20-20 + 0,1g of chelated iron per 5 gallon bucket.
This issue i thought was nute burn and iron deficiency but i backed down on the ec and added chelated iron + foliar sprayed iron sulphate(today) + foliar sprayed calmag (4 days last week). 3 out of 4 plants are doing great with nice green leaves but one plant shows this yellowing of the tip
Any ideas? Should i wait and see how it evolves?

 

[TessaMaria]

What does the rest of the plant look like?

 

[steve870]

the rest of the plant is quite normal, signs of a magnesium deficiency that hapenned early in the grow that was fixed but overall looks good

 

[steve870]

any ideas?

 

[PURPLEB3RRYKUSH]

Hi,
This is my second grow, i am growing in coco Multifeeding ec@ 1.06 and ph 5.8 to 6.2. Calmag+ 20-20-20 + 0,1g of chelated iron per 5 gallon bucket.
This issue i thought was nute burn and iron deficiency but i backed down on the ec and added chelated iron + foliar sprayed iron sulphate(today) + foliar sprayed calmag (4 days last week). 3 out of 4 plants are doing great with nice green leaves but one plant shows this yellowing of the tip
Any ideas? Should i wait and see how it evolves?
View attachment 4474906

Looks similiar to my issue, mines worse most edges on my fans r crisp, im guessing potassium

 

[PURPLEB3RRYKUSH]

Could be P maybe as I use megacrop and shots lacking P on my end. Someone experienced help us both lol. It's mainly affecting my middle to top fans were they get more light.

 

[PURPLEB3RRYKUSH]

Think my issues similar.

 

[steve870]

i will be trying to up my ec a bit.Since my calmag issue is resolved

 

[Trout2012]

I recently had a similar issue didnt quite fit the normal. My ppm were good, so I added cal mag about a tsp of bloom. It straightened right up. They say hydroton doesn't require cal mag. But last time I checked the hydroton hadn't grown at all!! I'm growing weed and giving it what it wants!!

 

[HolyAngel]

Yeah looks like it could maybe be potatssium, that's the closest thing I can find.

 

[OldMedUser]

Early signs of nute burn if anything. What makes you think it needs iron?

Could be leaching nutes out of the leaves if you spray often. Should never spray your plants unless battling bugs, mildew or attempting to fix a nutrient deficiency and rarely for the last one.

 

[steve870]

well it definitely needed iron because it had intervenal bleaching and had plenty of magnesium. Plus, these signs stopped when i added chelated iron to my mix. Now, those signs are different and are persistent.

By the way, plants do not Leach nutrients by the leaves. It doesn't work like that, if it was the case plants would be loosing nutrients every time it rains

 

[OldMedUser]

You can definitely leach nutes from leaves with excessive spraying.

Low iron shows up as yellowing in newer growth starting at the back end of the leaves. Low Mg starts with interveinal yellowing in older fan leaves as it's a mobile nutrient and gets stolen when it's low in the media where Fe is immobile and a lack in the media affects newer growth first. Older leaves already have all the iron they need and won't give it up.

 

[fragileassassin]

You can definitely leach nutes from leaves with excessive spraying.

Low iron shows up as yellowing in newer growth starting at the back end of the leaves. Low Mg starts with interveinal yellowing in older fan leaves as it's a mobile nutrient and gets stolen when it's low in the media where Fe is immobile and a lack in the media affects newer growth first. Older leaves already have all the iron they need and won't give it up.

Wow, never seen the part about how long the mag def takes to show thats crazy. I would imagine its shorter with hydro though right?

 

[OldMedUser]

Wow, never seen the part about how long the mag def takes to show thats crazy. I would imagine its shorter with hydro though right?

Low Mg takes longer because it's mobile and the plant can steal what it needs from older leaves to keep the new sgrowth healthy until the condition becomes chronic.

Immobile nutes show fast in new growth as the plant can't get it from anywhere but the media it's grown in or from a foliar spray.

Mobile nutes are NPK, Mg and Zinc and the plant can steal them from older leaves to support healthy new growth. Everything else is immobile and must be supplied as the plant needs them. In most cases it's nutrient imbalance or pH way out of whack causes lockouts so the plants can't absorb what it needs. I'd wager 90% of pH being out of whack is tap water building up it's minerals in the soil creating toxic conditions of high alkalinity after many waterings.

When that is the cause pHing your feed water down a few decimal points won't do a damn thing to change the pH in the root zone. It needs to be flushed well and hit with a good dose of pH 5 water to change things to the better. That's why getting good runoff is so important when using hard water. The harder your water the more runoff you want each time you water or feed. If using a good organic soil and using water only you don't want to be flushing the nutrients out so better water means less runoff needed and if pure water you really don't need to get any runoff if you don't want.

 

[fragileassassin]

Awesome. I always enjoy your posts like this. So informative and you're always teaching me new stuff even if you don't know it lol.

 

[steve870]

Plant cells have transport proteins in their cytoplasmic membrane. Thus they are able to "pump" nutrients against the concentration gradient using atp and have a more concentrated cytoplasm. Those nutrients can't leave the plant once they are inside thus making it impossible to leach nutrients by the leaves( except for small amounts of metabolites) Roots have a similar system of proteins pumping nutrients and water into the vascular stele through two cytoplasmic membrane, they have no choice to do that because of the casparian strip blocking the intercellular spaces. That is a way of controlling what goes in or not. Though, don't get me wrong, it's not bomb proof as overwatering will putting an excessively high osmotic pressure, bypassing the casparian strip and damaging the plant cells

 

[steve870]

Small update here, i added some hydroponic nutrients containning sulphur. After checking all my nutrients, the only one missing was sulphur and after adding it to my mix yellowing of the leaf tips subsided and i raised ec to 1.6 which they responded great