I can't find this issue anywhere - coco grow and yellow spotting

[thc111]

Hey everyone,

I have a problem with my 3 week old autos.

I'm running Canna a + b, and calmag (starting at 250ppm, now 500ppm total), basically following manufacturers chart. PH is 5.8 - 6.0, 70% RH, 75f temps.

I've basically had this problem since seedlings - tiny yellow spots that continue to spread (eventually twisting the leaf slightly), and streaks of yellow, which are worse on the old (bottom) leaves. I've checked with other forums, and the advice varies wildly:

-Lights too bright, too low (changed)
-EC too low (changed)
-Add potassium bicarbonate for buffer (haven't done this yet)
-I have Zn/B deficiency with excess K
-I have Manganese toxicity

Nothing seems to help and I don't understand why I'm having this issue following the same manufacturer directions as others?

I've checked for pests constantly and cant see anything. Help!

 

[Phytoplankton]

Have you taken a loop and looked under the leaf? Those tiny spots look like it could be mite or even thrip damage.. spider mites are very small, and can be tough to see.

 

[Roy Growin]

Yes, look with a jewellers loupe for absolutely anything on the back of the leaf; be it a bump, a speck of green, bit of dirt... mites are very hard to spot unless you're a ladybird which, since you can evidently type, you're probably not
The rest of the leaves look mostly ok, so probably not nutrient related

I have never measured ppm, you should be on 2-3ml/L of AB and a bit of seaweed helps a lot

-Lights too bright, too low (changed) - totally irrelevant
-EC too low (changed) - nope
-Add potassium bicarbonate for buffer (haven't done this yet) - stoned fucker, don't do that
-I have Zn/B deficiency with excess K - may have a point, but nah
-I have Manganese toxicity - rubbish

 

[Keffka]

I see this from time to time when people do foliar sprays at lights on and it burns the leaves. I personally see this on my own plants when they want more calcium

Both of the things I’ve circled in this image also look related to calmag. What order are you mixing your calmag in? it should be the first thing you mix in if you’re not doing it like that. Also @Roy Growin mentioned your feed, are you hitting the numbers he mentioned?

 

[Bill284]

Hey everyone,

I have a problem with my 3 week old autos.

I'm running Canna a + b, and calmag (starting at 250ppm, now 500ppm total), basically following manufacturers chart. PH is 5.8 - 6.0, 70% RH, 75f temps.

I've basically had this problem since seedlings - tiny yellow spots that continue to spread (eventually twisting the leaf slightly), and streaks of yellow, which are worse on the old (bottom) leaves. I've checked with other forums, and the advice varies wildly:

-Lights too bright, too low (changed)
-EC too low (changed)
-Add potassium bicarbonate for buffer (haven't done this yet)
-I have Zn/B deficiency with excess K
-I have Manganese toxicity

Nothing seems to help and I don't understand why I'm having this issue following the same manufacturer directions as others?

I've checked for pests constantly and cant see anything. Help!

Welcome to 420magazine my friend
Coco requires you add calmag to your plain water first.
Then nutrients then set ph then feed to run off every day.
Are you doing this?

Stay safe
Bill284

 

[thc111]

Hey all, thanks alot for your replies:

I add calmag 1st, at 1ml per litre.
I have been using 2.3ml/l of both a and b, and also a tiny amount of seasol in my last two waters.
I water to run off each time, twice per day.
I don't spray onto leaves, although from time to time some splashes on.

I'll buy something to zoom in on the leaves just to double check for pests, just in case. My tap water is quite soft, 30ppm, so perhaps I should up my calmag to 1.25mg/ml as well?

 

[Bill284]

Hey all, thanks alot for your replies:

I add calmag 1st, at 1ml per litre.
I have been using 2.3ml/l of both a and b, and also a tiny amount of seasol in my last two waters.
I water to run off each time, twice per day.
I don't spray onto leaves, although from time to time some splashes on.

I'll buy something to zoom in on the leaves just to double check for pests, just in case. My tap water is quite soft, 30ppm, so perhaps I should up my calmag to 1.25mg/ml as well?

I’d add what is recommended by the manufacturer for your calmag.


Stay safe
Bill284

 

[Absorber]

Looks like pest damage to me

 

[bluter]

Looks like pest damage to me

i agree it's looking like mites. get to them now and everything will be fine.

 

[Absorber]

i agree it's looking like mites. get to them now and everything will be fine.

Yep or could be a thrip

 

[bluter]

Yep or could be a thrip

thrips usually leave heavier damage.

 

[Absorber]

thrips usually leave heavier damage.

It depends on the size of the thrip too

 

[thc111]

Thanks again everyone,

I can confirm that I don't have any mites/bugs as I checked every leaf fully with a magnifying glass. No movement, and no insects. I must admit that I did see 3 - 4 small yellow flies around plants about a week ago, which I killed (and haven't returned).

The CalMag is FloraMax ca-mg-fe, which is from a different manufacturer. It recommends 1ml per litre. The Basic nutes are Coco Cana A + B.

I have read that CalMag isn't always necessary using Coco Cana A + B. I did drop the CalMag to 0.25ml (1/4 dose) in case it was too high a few days ago - it didn't seem to help. At this point I've been testing a variety of protocols to see which is causing the issue.

 

[bluter]

Thanks again everyone,

I can confirm that I don't have any mites/bugs as I checked every leaf fully with a magnifying glass.

magnifying glass won't cut it. you need a min 30 - 40x jewelers loupe. up to 60x works better but is slower to search. the bugs you are searching for are semi-microscopic. if you don't have a loupe you'll need a microscope lol.

edit : for comparison they are about 70% smaller than dust particles

 

[thc111]

Could it hurt to try and use some sort of pesticide just in case?

 

[bluter]

Could it hurt to try and use some sort of pesticide just in case?

you have to be careful. go after them now in veg. once in flower you could consume the pesticides after harvest and your options are none to nil.

sns, neem oil, a 50/50 iso spray, and a hotshot are all control options at present. act soon as the window to treat the issue is shorter with autos than a photo.

 

[Absorber]

you have to be careful. go after them now in veg. once in flower you could consume the pesticides after harvest and your options are none to nil.

sns, neem oil, a 50/50 iso spray, and a hotshot are all control options at present. act soon as the window to treat the issue is shorter with autos than a photo.

Or you could use predatory mites

 

[thc111]

Ok cheers all - I'll pick something up from my hydro store tomorrow

 

[bluter]

Or you could use predatory mites

especially if organic and perpetual.

 

[bluter]

Ok cheers all - I'll pick something up from my hydro store tomorrow

your treatment window is 3wks. it takes that long to eradicate them. you can kill the live ones but their damn offspring eggs hatch after then you have to kill the next gen. it's about a wk a gen and takes 3 gen to do the job.

it helps to use 2 or more treatment options and rotate them every couple days.

edit : unless you go organic. my methods would kill the friendlies lol