Yellowing leaves

[NoFksNate]

Hi guys,

Perhaps I'm stressing too much, this is my first grow.

Seedlings were going really well (2 weeks old) however now the first 2 sets of leaves are yellowing (almost looks like bleaching from the sun). They are in coco and in the sun during the day (intense summer sun for about 10 hours) then I bring them under lights for an extra 4 hours in the evening.

When they started yellowing 2 days ago I reduced the amount of light hoping they would recover, but they are continuing to yellow...

I'm running 1/2 nutes + calmag supplement.

Am I stressing too much or is there an issue here??

Thanks

[JeffInCanada]

Could be too hot under that sun for the little plant. Soil looks a little dry too. Read and water as directed in the link below. Leave it under the inside lights (if the air temperature is better) until you see recovery and the plant gets a little bigger. Don't worry about the nutes until you get this corrected.

[NoFksNate]

Could be too hot under that sun for the little plant. Soil looks a little dry too. Read and water as directed in the link below. Leave it under the inside lights (if the air temperature is better) until you see recovery and the plant gets a little bigger. Don't worry about the nutes until you get this corrected.

Thanks Jeff,

It has been about 35degrees each day so hopefully its just a little too much heat / sun and not something more serious.

Just confirming - no nutes (only water) until the seedlings starts to look happier?

Thanks

[JeffInCanada]

That's what I would do. Only water to see if it greens back up (or at least the new growth looks nice and green) in the cooler air. Follow the watering procedures and keep an eye on it. 35 Celsius is pretty hot. The plant will need to get a bit bigger before putting back out there. I'm in Canada...we're in freezing temperature now and have been for a while. 35 Celsius sounds so good to me right now though.

[NoFksNate]

Thanks again

[CaptainWiese91]

Is this soil or coco that medium ?

if it’s coco, and you didn’t add any nutes, I would think this is why you have symptoms

[NoFksNate]

Yes, ph is about 6.5

[CaptainWiese91]

It’s a little high for a coco grow ?
Your range is 5,5-6,5 so you are definitely in the high end.
Maybe take it down to 5,8-6,0, see what happens. You will not hurt the plant by doing that

[NoFksNate]

Is this soil or coco that medium ?

if it’s coco, and you didn’t add any nutes, I would think this is why you have symptoms

Hi,

Yes it's coco, I'm using half nutes.

[CaptainWiese91]

And You maintain the PH in the right range ?

[NoFksNate]

Yes, ph is about 6.5

[dilvish]

Ph should be 5.5 -6.5. 6.0 would be optimal for coir. It looks underwatered and yes, likely it is having heat issues if it's in 35C sunlight 10 hours a day. Seedlings don't need that much light. Stick it in the shade on those 35C days as long as it's still light enough (not shade that is blacked out!

Yellowing and pale leaves is likely a nitrogen deficiency. When growing in coir you need to feed right away. Start feeding full strength and see what happens. Flush the coir first using properly PH'd water.