How to fix yellow tips

Louder is halfway right, go higher with your humidity you are under HID they radiate quite some heat to be in a good range Google VPD grow HID and you will find charts for temperature and humidity to go with. If it's hot and dry plants use up more water than nutrients to cool them selves down the salts stay in the medium letting the ec rise, in your case pre fertilized soil. This might be causing your burned Tipps. Going colder could be challenging with your light setup, going more humid could help you out and be enough

Boost your humidity and drop your temperature for starters. Looks too hot and dry for this stage looking at your hygrometer.

Give only water for a week