First true leaves starting to get lighter colored, time to start feeding?

Hello!
This is my first grow and second thread on this website.
I'm 18 days from sprout, growing in a green house, in a pot that's a tad too big.
I'm using organic soil, I guess there's a lil bit of nutes already in there but not the slow release type.
For the light, I only have sunlight and I only give her plain rain water (I don't know the ph)

So I went to water my plant this morning and noticed the cotyledon and the first true leaves started turning a yellower shade of green. I heard it was normal for the cotyledon but I'm not sure about the other set.

It's nothing alarming really, but I'd like to identify what caused this to be able to get them back to normal as soon as possible. The new growth looks fine too.
I'm not sure when I'm supposed to start giving her nutes as it's an autoflower and I heard those dont need quite as much as the photoperiod plants but I figured it could be my problem. But when I look at the deficiencies guide, lighter leaves can be caused by a lot of things!

it's a tiny bit more noticeable in person but even in the picture you can tell a small color difference between the first true leaves and the first true fan leaves.
any insight would really help me out, thanks!

Looks fine to me, the inside new growth shoots are generally slightly lime green anyway....
For 18 days from sprout, Id say your doing just fine.
IMO, there's no such thing as to big of a pot, then again, I'm not familiar with autos AT ALL.
Large pots are VERY easy to overwater in the plants early stages. For every 1 seedling that dies from dehydration, thousands upon thousands perish by drowning in soaking wet medium, not allowing proper gas exchange, to develop healthy root systems...
The mindset ought to be growing ROOTS at this stage.... here again I know squat when it comes to autos!

When you say organic soil, which brand exactly? Or did you make it?

well I'm not familiar with anything grow related as it's my first one so don't worry, I'm sure you know a lot more than me.
I was told it was too big because there was no way an auto could fill this volume with roots in it's less than 3month lifespan. but nothing bad for the plant, just inneficient soil-quantity-wise.
about the overwatering thing I couldn't agree more. I had another one in the same kind of pot and I lost it to damping off...
Maybe once but not twice, lesson learned!

for my soil, it's DCM ecoterra bio soil.
it says it has enough organic amendments for 100days,
It's supposed to get the ph around 5 to 6.5
the npk is 7 - 7.5 - 8

I'm just wondering when I should start giving her nutes.

Cannaprentice said:

well I'm not familiar with anything grow related as it's my first one so don't worry, I'm sure you know a lot more than me.
I was told it was too big because there was no way an auto could fill this volume with roots in it's less than 3month lifespan. but nothing bad for the plant, just inneficient soil-quantity-wise.
about the overwatering thing I couldn't agree more. I had another one in the same kind of pot and I lost it to damping off...
Maybe once but not twice, lesson learned!

for my soil, it's DCM ecoterra bio soil.
it says it has enough organic amendments for 100days,
It's supposed to get the ph around 5 to 6.5
the npk is 7 - 7.5 - 8

I'm just wondering when I should start giving her nutes.

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I like to let my soil get pretty dry when they're young, to encourage roots to look for water. So, I don't water on any kind of schedule, I pick up the plant to see how light it is. I actually do the weight test through a lot of the grow, until the plants get too big. This really helps with overwatering issues.

Cannaprentice said:

well I'm not familiar with anything grow related as it's my first one so don't worry, I'm sure you know a lot more than me.
I was told it was too big because there was no way an auto could fill this volume with roots in it's less than 3month lifespan. but nothing bad for the plant, just inneficient soil-quantity-wise.
about the overwatering thing I couldn't agree more. I had another one in the same kind of pot and I lost it to damping off...
Maybe once but not twice, lesson learned!

for my soil, it's DCM ecoterra bio soil.
it says it has enough organic amendments for 100days,
It's supposed to get the ph around 5 to 6.5
the npk is 7 - 7.5 - 8

I'm just wondering when I should start giving her nutes.

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I wouldn't put much faith in the soil having 100 days of fertilizer. At most, you have about 3 weeks, while the plant is small.

That's what I thought.
Do you have any idea what I should look after for good nutrients?
I'm not ready to put more than 100€ for the usual foxfarm stuff and I don't know anything about the topic.
I heard about calmag, and it seems to be cheaper, but I think I also need something with NPK right?
what would the appropriate numbers be?
does it promote root growth or do I need another product?
I heard autoflowers burn really easily but that giving them a just a tiny little bit really makes a huge difference.

Cannaprentice said:

That's what I thought.
Do you have any idea what I should look after for good nutrients?
I'm not ready to put more than 100€ for the usual foxfarm stuff and I don't know anything about the topic.
I heard about calmag, and it seems to be cheaper, but I think I also need something with NPK right?
what would the appropriate numbers be?
does it promote root growth or do I need another product?
I heard autoflowers burn really easily but that giving them a just a tiny little bit really makes a huge difference.

Click to expand...

I'm going to make this super easy for you, and you really don't need anything else until you've got some grows under your belt. Get General Hydroponics, Maxi-gro and Maxi-bloom. Very easy to use! All you have to do is follow their feedchart.

Ill second the nomination for the GH Maxi duo, been using that myself with good results.
Really good value for such a complete nutrient mixture, works great for my needs. I use the Bloom much more than the Grow, some use the Bloom entirely from start to finish....
Dry nutes are the way to go in my opinion, the time spent mixing them is well worth it.

Also worth noting, I have yet to run into a calcium or magnesium issue using the GH Maxis.

It looks fine. Get a bag of garden tone and mix a half cup or so into the pot.
Add a bit once a month to the pot and good to go.

Thanks you all so much for the recommendations!
I'll be on my way to try and find the closest thing possible available in my country and I'll order those for my next grow if I don't find it as is.
It seems like it's slowly progressing from bottom up and outside in. not crunchy, stunted, floppy or anything. Just a sightly yellow green. Looks like a pottasium deficiency to me, can anyone confirm?

it just looks like you need to feed them. start at half strength and work up from there.

Cannaprentice said:

Thanks you all so much for the recommendations!
I'll be on my way to try and find the closest thing possible available in my country and I'll order those for my next grow if I don't find it as is.
It seems like it's slowly progressing from bottom up and outside in. not crunchy, stunted, floppy or anything. Just a sightly yellow green. Looks like a pottasium deficiency to me, can anyone confirm?

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Leaves get blemishes and spots during the grow, so don't over react when you see them.

Use the GrowWeedEasy plant problems guide. If you familiarize yourself with the different symptoms, you'll be able to read your plants, and know what they need.

If you're getting light colored leaves at the bottom, either light isn't reaching them, or you need to bump up your nutes a bit. I'd bring the tds up 50ppm to 70ppm.

If you see a deficiency like this, it doesn't mean you need to add a specific nutrient (like calcium or potassium) to correct the issue. You just need to up your regular nutes, and bring up the levels across the board. Just get a common two-part nutrient package, and increase your tds.

Can't you get General Hydroponics products where you live? GH is probably the most popular nutrient companies. Surely, you can order them online. And, sorry for calling you "Shirley" LOL!

well she's not getting any nutes as of now so that's surely the problem ^^
I will give her the first feed this evening when I get back.
Thank you all for the help

Cannaprentice said:

well she's not getting any nutes as of now so that's surely the problem ^^
I will give her the first feed this evening when I get back.
Thank you all for the help

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Yeah, it's about time to start providing external nutes. Store-bought soil doesn't have much fertilizer, even if it says it has months worth. You really only have a week or two at most.

Cannaprentice said:

well she's not getting any nutes as of now so that's surely the problem ^^
I will give her the first feed this evening when I get back.
Thank you all for the help

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Start off around 250ppm, and work your way up from there, as needed. After adding nutes, wait a day or two to see if things are getting back to normal before adding more.

So it ended up being me not giving enough water to get a runoff leading to salt build up...
Lost 2 leaf sets to it.
lesson learned: you overwater with too high of a frequency not too much of a quantity

Cannaprentice said:

So it ended up being me not giving enough water to get a runoff leading to salt build up...
Lost 2 leaf sets to it.
lesson learned: you overwater with too high of a frequency not too much of a quantity

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Do this...right after topping off, pick up the plant and feel how heavy it is. Then, don't water your plant until the leaves just start to droop. Pick up the plant again and feel how light it is. After that, don't water until the plant is fairly light.

Cannaprentice said:

So it ended up being me not giving enough water to get a runoff leading to salt build up...
Lost 2 leaf sets to it.

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Nope.

How do you acquire salt build up in an organic soil when you haven't even been feeding them salt based nutes?

I think she looks fine bro.

well she certainly looked fine but it's not really the case anymore...
plus the growth have been really slow due to the shitty weather that was overcast 70% of the time.
here it is now, in all it's burnt glory. It started showing pistils too so it's gonna flower soon and it's still so small.
notice how the first two leaves are just gone and the third set tarted burning.
I feel like it stopped now but I took time to figure it out.


I started a new grow indoors and it's going much much better.
At 7days old, my new seedling is bigger than this plant was at 2weeks old!