Dark green leafs with burned tips

Hi guys,
I have an issue with my plant.
I know, as I growed before, that dark green leafs and burned tips aren't good sing.
This is what happened:
First of all I didn't have good conditions to grow this girl at the beginning, and she grew tall.
When I assembled grow box with proper lights and vents, she was like 15cm tall but had only 2 small pair of leafs.
Then I red that it's ok to bury her, so her stem is long like 4-5cm above ground before first pair of leafs. I took a large pot, and I buried her almost to the bottom of the pot. There is maybe 7-9cm soil in between.
I also red that it's good idea to water her like 5cm in diameter when buried like that.
But, I was asking my self...when I water, lights will dry out surface but it will still be wet on the bottom of the pot, where the roots, of the weak plant, are. I taught it's gonna be root rot for example. But I didn't happened.
She started to grow very well instead.
New soil, I've added for a bigger pot, had some nutrients, and NPK was like 12-16-12, but it was opened last year, so I taught soil might lost some of it "power".
10 days after transplanting I've added half a dose of nuts(see in attached photos which). Plant then started to curve. Fan leafs started to curve outside-in, and she became dark green.
4 days ago I watered like before, just middle(5 cm), and then , day after, I've noticed some yellowness on tips.
I researched and I found out that yellow tips are showing light burn or too many nutes in soil.
I could say that tips of the plan were , maybe, way too close to the lights, and that's why they are kinda yellow, but I'm still worried about dark green color.
Yesterday I decided to flush her. Until this moment she's looking good.
Take a look at the pics.

I run 125W MH on 60x60 space closet. Temps are around 25C, and humidity is around 50-60%. pH level 6.2-6.5 . CO2 included.

Questions:
1. What do you think? What should I do?

2. As you can see , I've done some LST to it, and she is like 15cm tall at the moment.
I was thinking to cut off some of fan leafs below and some lower branches right now.
Should I do it now or should I let it get in "normality" before I prune her?

Thanks in advance.

Best regards

Post pictures

Oh sorry, I taught I did... there they are

Dark green + blanched tips = nitrogen excess

I’d Have to agree with @hotrodharley
Looks like beginning nitrogen toxicity

Doesn't look terrible.
Just cut back on your nutes.
There's still plenty in the soil.

thanks guys, I'll report what's going on...

What about pruning the leafs underneath?

She is kinda stuned... Fan leafs are turning more outside-in...

Should I flush her again?

There are no more signs of nutes burn anymore. She just had those tips burned, and now she is kinda ok, but still dark green

Just lay off the nutes.
The soil still has a charge.
Don’t flush. Don’t prune.
Just water.

ok man, thanks

Update
She looks much better, getting bushy, but still kinda dark green color at lower fan leafs.
Are they going to change color or will stay like that?

New tips are looking good.
Because she is in 6-7 liter bucket, I flushed her today with around that much plain water. Last time I waterd it was like 6 days ago, because plant was not that big for huge pot. But she progressed now a lot.
All post some pics tomorrow so you can tell me what do u think.

Excellent!
Those green lowers will feed the plant later. Not to worry.

Cool!
She grew really nice these days, so I decided to prune her lower branches and leafs. After 5 days she is getting bigger and bigger. I'll post some pics when my gf wake up
I think I could put her to 12/12 for about a week or soo...

Use water in between feedings to flush salt buildups they look alright

Hi guys.
Update.
She grew a lot for last time and I took some pics for you to tell me what do you think.

Yesterday, when I woke up and took pics, I saw the problem my baby have. Take a look at those kinda rust on the leaf. Today it's even worse. About 5-6 leafs get it too!!!

Is it iron deff or something else?

Also I turned 12/12 yesterday, and, because she was underwaterd(see leafs pointing down and the pot was very light), I watered her with some 1/4 of nuts for flowering. Was that mistake?

I'm really worried about her because that rust is spreading....

Help guys

boysetsfire said:

Hi guys.
Update.
She grew a lot for last time and I took some pics for you to tell me what do you think.

Yesterday, when I woke up and took pics, I saw the problem my baby have. Take a look at those kinda rust on the leaf. Today it's even worse. About 5-6 leafs get it too!!!

Is it iron deff or something else?

Also I turned 12/12 yesterday, and, because she was underwaterd(see leafs pointing down and the pot was very light), I watered her with some 1/4 of nuts for flowering. Was that mistake?

I'm really worried about her because that rust is spreading....

Help guys

Click to expand...

You still use veg nutes until 2 weeks into flower while they are still growing in veg.They don't switch over and start growing buds that fast it takes a while. At that point they are still in veg they can get burnt easily by bloom nutes right now, even in 2 weeks when nodes start develop still take it easy on the bloom and PK. In flower the deficiencies they should recover if you stop feeding them so much. That just happened to a buddy of mine, burnt the whole crop tastes horrible thinking he needed that many nutrients and they DON'T

But I've used nuts just once for veg stage, about two weeks ago. Now I switched to 12/12 and used some bloom nuts. That thing on leafs started before I added it.
It looks like some nuts deff....
Anyone?