HPS

Hey there AspPro, you have absolutely the right idea with the feeding , but i start by making a spray for them since you're in a soiless medium. you know at this stage the seedlings hardly have any roots so a spray is the logical way to go. you can even make it less strong than you think , and have great results. With the light you're on the right track aswell ! basically the small plants dont need that much light intensity. I'll turn on the full strength light during week 4. Hope this helps ! 🚀

As growers we tend to start feeding when the plant has its first set of true leaves. Which are fan leaves. if thats your only light your going to need to set it to a timer and keep it on for 18 hours a day and off for 6 most of us use timers to do that for us but you can do it manually if you remember Im pretty sure you cant dim hps bulbs you can change the whattage but not dim the bulb you dont wanting be wasting electric and a vegging plant does not need a shit ton of light I would keep it on 200 then in early flower up it to 300 and then in later flower last 6 weeks id put it on max :) Anyway best of luck of your first growing journey i bet your going to smash it :) 👊