Need help yellowing leaves and tips on new growth

Plant is 4 weeks old today
24hr light schedual
300W fullspec led
Nute npk 12 6 12
Ph 6.3-6.5 after adding nutes
Feeding every other water
Water every 4 days
Last watering added magnesium sulfate
Regular topsoil sterolized with steam
Mixed 30%perlite 10% white sand for drainage
No grow tent yet still need to buy one this is my first grow. Just want her to be healthy and comments or tips are welcomed

Anyone?