2 week old plant problem

It's inside a box inside a grow tent. Under a 105w cfl 20cm from horizontal bulb which has an 80mm fan underneath to distribute heat temps are 24-27 °C.
Prior to the above conditions there was a couple of days under 2x75w cfl's, with a fan directed vertical onto the plant.

The serrated leaves tips are pointing up, It was like this from seedling, looks like blackened tips, the lower first serrated leaves are yellowed and twisted the higher newer growth is not distorted.
I have been giving it rhizotonic, a few drops with a pipette before watering, I'm using coir&perlite mix.
Is this heat stress,light burn or nutrient deficiency.

It could be light burn, when they are that small it is hard to tell. The new leaves look so perfect, so just be patient. Make sure your containers have holes in the bottom so you get good drainage...

bladebeam said:

It's inside a box inside a grow tent. Under a 105w cfl 20cm from horizontal bulb which has an 80mm fan underneath to distribute heat temps are 24-27 °C.
Prior to the above conditions there was a couple of days under 2x75w cfl's, with a fan directed vertical onto the plant.

The serrated leaves tips are pointing up, It was like this from seedling, looks like blackened tips, the lower first serrated leaves are yellowed and twisted the higher newer growth is not distorted.
I have been giving it rhizotonic, a few drops with a pipette before watering, I'm using coir&perlite mix.
Is this heat stress,light burn or nutrient deficiency.

Spoiler: Ghost Train Haze #1

Click to expand...

I don't think it's bleaching. Unless you're putting the bulbs directly onto the foliage, cfls aren't going to give you issues like that. Most likely a ph issue. Maybe get a meter, and check your runoff.

The first runoff was more orange second was greener coloured

After 5 minutes in runoff water

Plants current condition one of the lower leaves are starting to curve upwards a lot more

A lot of perlite has come to the surface

did i read correctly that u were blowing the heat from the bulbs onto the plant?
Also like mr belvedere said the 2nd set of leaves look healthy and good.. i know its hard not to worry its a big problem for me too but give it a day or 2 and if the new leaves that come on are fine u should be doin ok id say..

bladebeam said:

The first runoff was more orange second was greener coloured

Spoiler: Paper Test

After 5 minutes in runoff water

Spoiler: Digital Test

Plants current condition one of the lower leaves are starting to curve upwards a lot more

Spoiler: 1 litre Flush

A lot of perlite has come to the surface

Click to expand...

Ph is looking good now. Hand fed Coco is just a really sensitive material in general, and when they are that young, they burn easy. The burnt growth will never recover, but now that everything is leveled out, you should see some killer healthy new growth. Nothing but greenage. Ph every feeding from now on to around 5.8ish to 6.3ish. I like dutch zone and/or floranova series for anything hydro. Good luck.

A a couple of days ago, I did have direct airflow through the bulbs onto the plant, enough to cause constant vibration. The light was a lot closer aswell, I estimate 10cm or less. no reflector above the twin 75w bulbs at that time.

present, single 105w with reflector, and some coats to keep heat inside. I need to keep electric cost down any heat I generate must come from the lights, when they grow more, I will put them in the tent under 250w mh.
This box is not the best, I am going to improve it atm I have 2 seeds at the back. planted yesterday.
It's had a 2L flush now, The PH water from asda/tesco is 7.9
I will see how the new growth goes. Is removing affected leaves going to make things worse.