Plant turning yellow, big fans brown spots, stretching, see pic

1st week added N nutes
2nd week flushed 2X
3rd week transplanted bigger pot with fresh soil, super flushed

still getting worse, it's a K2 and i'd like to save it ....

When you flip to 12/12? And if it yellowing its cause your flushing all the nutrients out the soil. It need nitrogen man.

not 12/12 yet , trying to get it green again 1st, young leaf tips r burned ? almost white
it's like it's on growth steroids

You didn't even tell us what lights your using?
They different strains? Some are hungrier than other strains but judging by size should be feeding em all. Put pics of all plants and your set up up. Will help.

And should be 18/6 really IMO. Most effective. Not to say 16/8 won't work...

just a CFL T-12 daybulb ghetto setup, basically all same soil and nutes,
till i tried to juice it up ... don't laugh it works ...

Not much light for that many plants many. how many watts got in total?
Im all for the ghetto set up man so dont worry! not a hater.
Tall one just a stretcher but needs a light feeding and would 12/12 her now as not much light or height by look of it.... OR top her? I topped my humboldt... 8colas but only 4 main ones.

lighting : using 12 40 watt T-12 full day light 4ft florescent tubes,
plant seems to be eating itself to keep up this growth, only its not 12/12 yet
maybe an auto flower ? got it from crappy and cheap Cannabisseeds (only 3 of 12 popped)

it's coming back, going green again , fresh dirt, bigger pot, did the trick i think ...