Help my little haze!!!

My little AHU2 is 4 weeks old and just started the 12\12 cycle under 400W HPS

She’s got some burnt tips at the lower leaves




But the upper leaves look worse.
They got these spots not just in the tips and they look a bit transparent where the spots are.


I just started to feed with Biobizz nuts and gave the dosage recommended in their feeding schedule.
BioGrow 3 ml\lt
Biobloom 1ml\lt
Alg-A-Mic 2 ml\lt
The water PH is 5.8 – but the runoff water is 6.3
EC is 1.7-1.8
She is about 30cm 12 inch from the bulb which is in a cooltube using 187 cfm inline fan
I also got a small fan blowing air directly at her


I looked into tutorials and I suspect over-fert or heat stress – please help

The

Burnt lower tips and the bit of twisting on the one leaf can be symptoms of nute burn (see the my seedling on the left in this pic from germ'ing in FFOF). You might dial down the nutes on the next feeding to about half strength and phase them in more slowly.

Thanks devOn
I just recalled that on the last time I fed them a few drops fell on that leaves.
So I guess that is a result of HPS + water with nuts.
But anyway I'm going to follow your advice - seems that lowering nuts is always agood advice.

That's a small plant in a big pot. Roots haven't explored all the soilmix in there yet. To encourage big root growth (for big final yield), you want to water and feed sparingly until the plant is much bigger.

Thanks for the tip Greengenes.
much appreciated.