Star Killer/Dosidos/Tropicanna Cookies

Current Setup: 2'x4'x5' tent 2 Morsen 185W LED's 4" 195CFM Vivosun ventilation 6" Optimus clip fan 5 gallon buckets/promix Strains Are: Tropicanna Cookies x1 Dos-Si-Dos x1 Star Killer OG x2 Haven't really decided what i wanna do just yet! Thinking I may try Main-Lining for the 1st time but kinda iffy on that because I don't think I'll have enough space within the 2x4... Have prior experience with LST, HST, ScrOG, Topping/FIMing will do some research & see if I got enough space to mainline 4 if not just gonna stick with what I know :P **As for nutrients was wondering if someone could recommend me something cheap/safe/effective for veg/flower that'd pair nicely with the soil i'm using (left a link on the picture above).. I don't have a ph meter & the soil i'm using does have a slow release fertilizer that can last up to 9 months so I'm not 2 sure what I should be using along side that... Thanks in advance for any recommendations!