I have 4 auto flower seedlings started in a 20 watt propagation and switched to 600 watt after 3rd set of leaves sprouted. Might need some tips. Have some yellowing and tip curling suspect I might have over fertilized. I went straight water and they seem to be improving. Should I use veg or bloom or both at this point? Is Mylar necessary? I have some I have not installed but the yellowing gives me pause. I am getting air pots for the others tomorrow. TIA