[Autoflower] Is this a Calcium deficiency?

Light: MH cooltube set to 300w (was 450w when problems began)
Medium: Canna Coco w/ perlite
Nutrients: Emerald Harvest 3 part (click for feed chart) + CalMag (click for feed chart)
Nutrient and water pH: 5.8
Medium pH: N/A
Temperature: 70-72F (21-22C)
RH: 45-55%
Strain: Fast Buds Feminized Auto Grapefruit
Age: 12 days (problems began at 10 days)

This occurred approximately 12 hours after her first full feed of (6-3-2-5mL/Gal [Grow-Micro-Bloom-CalMag]).

The morning of the feed:


12 hours later:

Looked like Calcium deficiency to me with a very sight nutrient burn on a few parts of the tips. Also some clawing showing too much Nitrogen.
I "flushed" it out with a gallon of 7mL/Gal of the CalMag that night.

The next morning there was a tiny bit of new growth with no additional burn indicating to me the problem should have been resolved and that it wasn't stunted too much.

(look at the very center growth compared to last pic).

Now, 24 hours later, without ANY additional water/feed, there is both new growth AND new damage.


The other 3 strains I have (Fast Buds GSC & Rhyno Rider, and Seedsman Kush Auto) are all fine for the most part with almost no signs of stress at all (there are signs of a bit too much light which is why I reduced it).



What do I do?
I was planning on feeding them tomorrow with:
Grapefruit: 4-3-1-6
Everything else: 6-3-2-6

I fed them early this morning at 4AM with the above ratio because there was visibly more damage and I didn't want to wait until my normal feed time.

Here she is as of 1PM (9 hours after feed and 14 hours since the last picture).


The Nitrogen clawing doesn't seem to have gotten worse. There is new damage on the new leaf on the lower right. The new damage on the leaf on top was there last night before the feed.

I'm still not sure how to proceed and am scared to feed this.

Here is a comparison with how the Kush Auto is doing.

jeesas, don't use all that shit on such a small plant. It is not looking healthy.. any chance you can leave the pot outdoors a day or 3? Bit of mottled sunlight spectrum and a fresh breeze is all they need sometimes.

ANC said:

jeesas, don't use all that shit on such a small plant. It is not looking healthy.. any chance you can leave the pot outdoors a day or 3? Bit of mottled sunlight spectrum and a fresh breeze is all they need sometimes.

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No chance of bringing it outside I'm afraid.

I'm thinking now that my issue is precisely my due diligence. I do not really let the pH waiver from 5.8 and try to be exact every time. I will try letting it change a bit.

Next feed:
Grapefruit: 3-2-1-7 @ 5.6pH
Everything else: 6-3-2-7 @ 6.0pH

I just friggen ballpark it. If it is close enough to 6ish, I don't mess with it much.
For veg, I just use a simple liquid organic garden feed no pHing.

ANC said:

I just friggen ballpark it. If it is close enough to 6ish, I don't mess with it much.
For veg, I just use a simple liquid organic garden feed no pHing.

Click to expand...

The pH here is pretty high. The pH of the tap is around 7.5 and after adding nutes, it can go up above 8. I definitely wouldn't want to do that unless the mix had something that brought the pH down.

How can you tell if a plant wants MORE nutrients without it really falling into a deficiency?

For example, this is my GSC as of today:


I figure that since the light green is in newer growth and not old growth, it isn't Nitrogen, but is instead Manganese. It wants more Manganese right? Since I have plenty, it just wants the pH to be brought down a bit to be able to use it right?

Am I thinking about that correctly?

That yelowish green is a good sign to add more food or less food more often... always increment small at first...

kbone123 said:

The pH here is pretty high. The pH of the tap is around 7.5 and after adding nutes, it can go up above 8. I definitely wouldn't want to do that unless the mix had something that brought the pH down.

How can you tell if a plant wants MORE nutrients without it really falling into a deficiency?

For example, this is my GSC as of today:

I figure that since the light green is in newer growth and not old growth, it isn't Nitrogen, but is instead Manganese. It wants more Manganese right? Since I have plenty, it just wants the pH to be brought down a bit to be able to use it right?

Am I thinking about that correctly?

Click to expand...

it's a sign they're hungry, feed them...
get some ph up and ph down, and use them. it won't hurt anything, it's good stuff, you don't use enough of it to change your feed ratio, it's a negligible amount.
keep it simple...the more you think, the more things you're going to end up having to fix.....

Roger A. Shrubber said:

it's a sign they're hungry, feed them...
get some ph up and ph down, and use them. it won't hurt anything, it's good stuff, you don't use enough of it to change your feed ratio, it's a negligible amount.
keep it simple...the more you think, the more things you're going to end up having to fix.....

Click to expand...

Thanks. I already have pH up and down. That last post was in regards to how much I need to adjust it.

i've always ph'ed coco to 6.1

i really think the light color is from rapid growth, and they could benefit from a little more food

I decided to change it up and give them half-strength feed with overflow every time instead of water in between. I added Silica as well from GH.

Grapefruit: 1.5 - 1 - 0.5 - 3.5 - 0.75 @ 5.6pH
Everything Else: 3 - 1.5 - 1 - 3.5 - 0.5 @ 5.6pH

I figure that we like to eat every day instead of a lot every other day. If the plants don't like something, it should be less damaging if it's half-strength I assume.

I'll fluctuate pH regularly as well. Will do 6.1 next time.

I have been keeping these autos under 24/0 light. I just had a power outage for 2 hours. Will this cause issues or will they likely behave normally?

no, won't hurt. needs to be a lot longer than 2 hours to do anything

With such small plants in such big pots one good feed should last for at least 2 - 3 weeks. Shouldn't even need water for a couple weeks if you've soaked the whole pot good with the first feed.

At the rate you're going you're going to kill them with kindness.

A lot of seedlings exhibit odd leaves at first then once settled in grow just fine. To start finding 'deficiencies' this early and mess around trying to fix a non-existent problem will do more harm than good.

Could just be a bad seed too.

Update on the Grapefruit:
After feeding with the half-strength (of previous feed), adding Silica, and lowering pH down to 5.6, she seems to be responding well. She never really stopped growing, but just looks REALLY sickly. However, the new growth is finally starting to look a little strong! I'm hoping that this means she DOES have a strong root structure going, but just wasn't getting what she needed.



I will also take some of OldMedUser's advice and relax on watering for a bit. However, I have been hearing two sides to watering regarding Coco. I hear that it's both okay to constantly overflow water every day as well as let it go dry between watering. I can't help but feel like letting it go dry is a hindrance to their growth as it is essentially hydroponic growing with a physical medium there.

Legitimate question: How does a DWC plant react if left without water for a day or so?

kbone123 said:

Update on the Grapefruit:
After feeding with the half-strength (of previous feed), adding Silica, and lowering pH down to 5.6, she seems to be responding well. She never really stopped growing, but just looks REALLY sickly. However, the new growth is finally starting to look a little strong! I'm hoping that this means she DOES have a strong root structure going, but just wasn't getting what she needed.

I will also take some of OldMedUser's advice and relax on watering for a bit. However, I have been hearing two sides to watering regarding Coco. I hear that it's both okay to constantly overflow water every day as well as let it go dry between watering. I can't help but feel like letting it go dry is a hindrance to their growth as it is essentially hydroponic growing with a physical medium there.

Legitimate question: How does a DWC plant react if left without water for a day or so?

Click to expand...

Hey dude.

Its all about pot size, and drainage with coir.
Coir breaks down, and composts like other organic material, and has an extremely high cation exchange capacity because of this. It also sucks up water, and new cations like a sponge.
Wet coir all the time, without drying out a little is a bad thing. I guarantee the centre of that pot is always wet.
Im with Oldmed here. Let it dry out for at least a few days.
Starting a seedling in a pot that size is a challenge. Especially with coir.
Let it get bigger. It has improved a lot since the first picture.
You wont be able to fix deficiency, on a plant that small, in a pot of coir that large easily at all. Most likely itll cause more harm than good.
Let it veg some more. Then start fine tuning. You need more roots in that pot first.

kbone123 said:

Update on the Grapefruit:
After feeding with the half-strength (of previous feed), adding Silica, and lowering pH down to 5.6, she seems to be responding well. She never really stopped growing, but just looks REALLY sickly. However, the new growth is finally starting to look a little strong! I'm hoping that this means she DOES have a strong root structure going, but just wasn't getting what she needed.

I will also take some of OldMedUser's advice and relax on watering for a bit. However, I have been hearing two sides to watering regarding Coco. I hear that it's both okay to constantly overflow water every day as well as let it go dry between watering. I can't help but feel like letting it go dry is a hindrance to their growth as it is essentially hydroponic growing with a physical medium there.

Legitimate question: How does a DWC plant react if left without water for a day or so?

Click to expand...

(feel like letting it go dry is a hindrance to their growth ) in veg watering to much does exactly that stunts growth even in coca. i have only done 3 grows indoor so far and from what i have seen my self is. if you keep your coca too wet all the time the roots don't bother growing. you will end up with a few roots on a small ball and that's it in flower its fine to water the shit out of them every day but in veg watering every day is only going to make your plant stay small. us new ish growers cant help watering toomuch because we are dumb and impatient to wait 3 days before watering.

How does a DWC plant react if left without water for a day or so? why would you pull the roots out of water for a full day. it would die due to no oxygen maybe if you misted the roots every few hours it be ok but just dont even consider leaving a dwc plant to go dry

Tim1987 said:

Hey dude.

Its all about pot size, and drainage with coir.
Coir breaks down, and composts like other organic material, and has an extremely high cation exchange capacity because of this. It also sucks up water, and new cations like a sponge.
Wet coir all the time, without drying out a little is a bad thing. I guarantee the centre of that pot is always wet.
Im with Oldmed here. Let it dry out for at least a few days.
Starting a seedling in a pot that size is a challenge. Especially with coir.
Let it get bigger. It has improved a lot since the first picture.
You wont be able to fix deficiency, on a plant that small, in a pot of coir that large easily at all. Most likely itll cause more harm than good.
Let it veg some more. Then start fine tuning. You need more roots in that pot first.

Click to expand...

Hey thanks for that. I've never heard the term "cation exchange capacity", but it has lead me to a whole new branch of research to explore. Thank you!

I'll see if I can muster the courage to let them go without anything more for a week and see how things go.

kbone123 said:

Hey thanks for that. I've never heard the term "cation exchange capacity", but it has lead me to a whole new branch of research to explore. Thank you!

I'll see if I can muster the courage to let them go without anything more for a week and see how things go.

Click to expand...

plant be like hay give me a drink then it be like now go the fuk away for a few days then give me attention