Seedling Yellowing Problem

BudBogart said:

You have determined it must be light, water, or oxygen related. It must have something to do with your grow box.
With those parameters no one has been able to offer suggestions that you consider. You are looking for a professional to agree it must be your grow box. If it's grow box related you will need to describe your grow box, lighting and cooling, ventilation, etc. it's frustrating when things go south. Hang in there.

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I have solved the problem and it was my grow box..somehow the are starving of oxygen..I've opened the door up and left it a jar for a few days like i used to be before i installed the cooling system. They are now coming back to life!

So now my question is why is the exhaurst fan blowing 100mm of air into the box not allowing enough oxygen to get to the roots?

Here is a pic of my grow box it should be pretty self explanatory how it works.

Or is it lack of co2 in a closed box?

Leebone said:

Or is it lack of co2 in a closed box?

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Fellow grower, I am neither a tent grower nor a professional, but I am thinking that you were not having problems until you started closing the tent fully.
To my eye, it still resembles simple nitro shortage, and I completely disagree that a seedling is good for 3-4 weeks before needing some nutrition. My seedlings started in non fert free soil go 10 days -2 weeks tops before starting to yellow.
Do you have updated pics?

@BudBogart is correct. .. your plant needs fresh air.

Since you are trying to push air into your tent, you are simply creating back pressure... What you need to do, is pull the air out of your tent.

Turn your fan around.

BudBogart said:

Fellow grower, I am neither a tent grower nor a professional, but I am thinking that you were not having problems until you started closing the tent fully.
To my eye, it still resembles simple nitro shortage, and I completely disagree that a seedling is good for 3-4 weeks before needing some nutrition. My seedlings started in non fert free soil go 10 days -2 weeks tops before starting to yellow.
Do you have updated pics?

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Yes it did start on this grow since its been closed..

I guess it just depends on what you grow in..
I started outdoors in horse shit soil mix and first lot went all the way to flower with no nutes...buds were crap and tossed them but no yellowing...
The next was a seed that had dropped off on of those plants and i just let it go watered every now and then but didn't really care after my first failure.
That have no nutes until flower and was potent and sticky as..air and leafy buds but potent!
That's still the best plant ive every grown even though I've had alot bigger with alot more bud but still not as potent as that one..

I believe most of the time it is strain dependent on how it will turn out.

I'll add some updated pics soon

ken dog said:

@BudBogart is correct. .. your plant needs fresh air.

Since you are trying to push air into your tent, you are simply creating back pressure... What you need to do, is pull the air out of your tent.

Turn your fan around.

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I have an intake and an outtake.. so you think i should just turn the intake off and only run the outtake only?
Also the intake is the same exhaurst fan as the outtake im just using the air it blows out of the duct..is this possible to do or is this the problem?
And wont there be very little air getting in there of i close it and turn the intake off?

You don't need a fan on the intake... Just let your exhaust fan draw fresh air into your tent through your intake hole.

The issue is not lack of oxygen, it's lack of fresh CO2 to replace the CO2 that your plants have used up.

Updated pics after a trim on the ones that brunt.

ken dog said:

You don't need a fan on the intake... Just let your exhaust fan draw fresh air into your tent through your intake hole.

The issue is not lack of oxygen, it's lack of fresh CO2 to replace the CO2 that your plants have used up.

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Thanks heaps mate I've turned the intake off and doors been closed for aĺmost two days now and they are still looking good hopefully they can play catch up now..