small seedlings yellowing - loads of info

Hey all, so this is my second post on same issue but i cant seem to fix it!

first of all some info here:

600w hps <-- many people have said that HPS is bad for seedlings whilst others are saying that its no problem.. its also the only option i got so..

tent 1m x 1m x 2
seedlings 14 days old now (from seed)
growing with canna coco
humidity between 40-60%
temp: messured In shadow at the height of the plants 27-28 C
10 seedlings
6x critical mass
1x fem lockstock x skunk
3x dna la woman

i got really nice air flow in the room.. both in and out..

some info about my watering

i have been watering with just water (PH 5.9-6.1) until 2 days ago when i started to feed with bout 1.2 EC (bit high i know) and it burned (just barely) one of the plants and i checked the run off today and it said PH = 6.0~ and EC = 1.0

so ive learned to give a bit less nutes..


other then that i have to say that they turned light green at bout day 5-6 and have not cahnged at all..

i tried to use PH 5.8 at first then someone said i shud try to flush and go with ph 6.3.. so i did that but nothing has changed.. they didnt turn more yellow or more green.. just stayed the same light green fu*king colour!..


so i have now tried to start feeding them.. atm i cant say it has done much..

i also wanna say that it looks like my growth has been stunted..
they are at day 14 after the seeds sprouted up from the soil and they are JUST begining to get their second set of true leaves. is this normal??


so how can i get that nice green colour back?

ive tried to change PH down and up.. ive teid no nutes and now startet to give them some nutes (bit too much it seems).. but nuthing has changed yet..


any ideas?


ps: im guessing i burnt the fem lockstock seed, it turned a bit "crispy" brownish on one of the leafs (just a tiny bit on the tip of the leaf..) its still 99.999% alive and "well" except the colour :(