Cant tell the issue with new plants - first grow in coco

[thhc]

Hey everyone,

My first grow in coco, one plant is around 1 week old, the other two are 2 weeks old.

I've been feeding 2x daily to run off using RO water 6.0 - 6.2PH:

Canna A + B - started at 1/4 strength (0.5ml/L)
Floramax Calmag - started at 1/2 strength (0.5ml/L)

My light is around 25" from the plants at 80%, with a tent humidity of 60-70% (at 70-80F).

I noticed some yellow spots and some bumpy leaves a couple of days ago, so I doubled my nutes as I thought it may be a Calmag deficiency, but the problem only seems to be worse. My guess is light burn, or nute lockout? Can anyone help?

 

[thhc]

Sorry i forgot to mention im running around 400ppm (0.8 EC) which may be a little low?

 

[Imzzaudae]

Move light to 30 inches above. set power at 65%. Plant will be ok.

 

[thhc]

Move light to 30 inches above. set power at 65%. Plant will be ok.

Great! Thank you for the reply :)

 

[nicolajanjak]

do not use reverse osmosis water
thats is your issue
what is the start EC of your water (out the tap) ?
0.8mS of nutrients is not enough
I use 3.0mS in veg with rockwool with great results (my tap measure 1ms and I add 2ms of feed over it)
when the plants start to grow fast and drink everyday you need to runoff
imperatively

 

[thhc]

tap EC is

do not use reverse osmosis water
thats is your issue
what is the start EC of your water (out the tap) ?
0.8mS of nutrients is not enough
I use 3.0mS in veg with rockwool with great results (my tap measure 1ms and I add 2ms of feed over it)
when the plants start to grow fast and drink everyday you need to runoff
imperatively

Tap water is 0.07 (38ppm). I've heard so many conflicting reports about nutes. For example here the 2nd and 7th comments are saying start at 0.8 and work up to 1.2-1,6

 

[nicolajanjak]

calmag deficiency does not exist
its either calcium deficiency or magnesium deficiency (very easy to tel apart)
you don't have neither of the two

its more a buffering issue (pH)

your water is very soft
canna is designed for hard water

So you need to add a buffer to your solution
I usually advise sodium bicarbonate (baking soda) because it brings some sodium to the mix
But coco already contains a lot of Sodium so we will avoid it

The best option would be potassium bicarbonate
If I was you I would put my hand on some
Its cheap and 100% safe

Then you will be able to build a solid nutrient solution

And feed those plants
In run to waste 2mL/liter of A & B is the union minimum

At this age your plant should not drink twice a day
After each transplant you need to build a solid root mass before going to multifeeding
Letting the coco dryback some before feeding again

 

[thhc]

Ok thanks for your reply - I'll try doing as you've said.

 

[thhc]

Hi All,

Update:

I've got the nutes - calmag (1ml per litre), coco A+B (1.9mls each per litre) at 500-600ppm. PH 5.7-6.0. Moved the light up a few inches and dropped the intensity to 50% (200 - 250ppfd). Humidity is around 60-65%

I noticed some tiny little bright yellow flies in there (around 5) which I thought may have been the problem, so I killed them all off a few days ago, but the issue has continued. I noticed the the bottom leaves are the most affected (and they are dry-ish and slightly twisted), but I'm starting to get some tiny yellow spots on my healthy plants also.

The first two images show the older two plants (3 weeks), which have just started to have yellow spots on the top leaves.
The third image shows the youngest plant which has been the worst affected (it's one week younger than the other two).

This is an indoor grow in coco, so I didn't expect fungis/pests to be an issue?

Everything I'm reading is saying either calcium, a fungis, or a pest. Any thoughts? I don't want to stunt these autos

 

[Budclarkson]

Man I don’t think I’ll ever go pure coco and constant worry about the nutrients and water recipe. I swear you have to be Heisenburg to keep things right.

Soil mix is so much easier.

 

[BuffNuts]

First pics are Zn/B deficiency with excess K.

Last pic is Manganese toxicity. You'll never have good crops growing with these repurposed clown nutrients. Cannabis needs high B and Zn, and LOW Mn, that's why all these clown nutrients suck. The people whom developed them were NOT GROWING CANNABIS, just drawing up new labels for cheap ass stockpiled warehouse overflow tomato nutes.


Calmag fixes all. Until you lock out B Zn P and end up with forum grade boof.

 

[thhc]

First pics are Zn/B deficiency with excess K.

Last pic is Manganese toxicity. You'll never have good crops growing with these repurposed clown nutrients. Cannabis needs high B and Zn, and LOW Mn, that's why all these clown nutrients suck. The people whom developed them were NOT GROWING CANNABIS, just drawing up new labels for cheap ass stockpiled warehouse overflow tomato nutes.


Calmag fixes all. Until you lock out B Zn P and end up with forum grade boof.

That's a shame, because I've seen plenty of growers do well with this mix on here!

I've added some zn/b into my next two watering's to see if it improves the problem.

 

[thhc]

I thought I'd give an update to all - the plants are still

growing, but the condition is much more obvious now. I've sprayed for pests, as I've received advice that it is really tough to tell exactly what might be going on. One pic from each plant - the bottom leaves are obviously the worst.