Unknown problem, new grower need help

My plant is just over 3 weeks old, currently using 2 150W equivilant CFLs. Plant has been doing fine, until recently the leaves started to yellow on the edges, and the older leaves are turning a darker green. New leaves are looking good, but I'm still concerned about the old ones, and what needs to be done to prevent any further damage. Sorry for the lack of information, new grower, if you need more I can try to get it to you just let me know what would help.

Looks ok, I think you just burned it a little. Looks like its already recovering.

Keep watering with water only for a couple more weeks unless the plant shows signs of need earlier. You did burn it somehow, probably nutrient-heavy gardening soil. I sure hope you weren't dumb enough to try feeding it?

As an aside - what K are your CFL bulbs?

I was dumb enough to use mg soil with some feed. Glad to know its most likely burn. The cfls are 2700k im aware that its better to be in the 5000 range when vegging. Should I flush the soil or just switch to water only and let it run its course? My other concern is for 2-3 weeks old the plant looks small to me compared to others ive seen around its age. The stem is also red and very thin. Does the growth look stunted at all for being around that age? Thanks for the help you guys.

EDIT: Should I worry too much about getting higher k bulbs or will it not be a huge problem?

Still need help, and one more question, can I safely use superthrive without risking more burn?

If u burned it why u asking if u can put more shit in it?

it looks ok. the new growth look healthy. while she's still that young, water the area a few inches around the plant instead of soaking the entire pot.
make sure to use no more nutes until flowering begins-and then only lightly. GL

Don't do anything but plain pH'd water... Let your babies recover. Miracle Gro soil can be very "hot"... too much feed in the soil for a young seedling.

Good Luck, hope this helps