Can anyone tell why my seedling has gone yellow on the tips of the leaves

They have been inside on the window sill in full sunlight most of the day.
Temperatures dip to around 15c 57f at night.
I've been feeding them a very diluted water mixture using biobizz nutrients. Could I have used too much feed?

Also I started them in miracle grow indoor plant soil.

I have just transplanted them to a slightly larger pot with biobizz lightmix soil.

Any suggestions greatly appreciated.

It's an autoflower Northern lights I believe. Only 2 seeds made it out of the soil and 1 of them looks pretty much dead.

Oh my! I’d say maybe you fed it to much Or got to hot and dry for a while. It shouldn’t need fed just yet.

Nutrient burn and deficiency from to high ec for a lil girl

I would use plain water for a watering or two and let her go see if she bounces back it sucks cause autos are just so sensitive at these stages.

Thank you so much everyone!

I will try plain water for a while.