I have a simple effective pretty common method. I just use ocean forest from seedling or cutting and transplant every 2-3 weeks. 16 oz. party cup. Then 1 gallon nursery pot. Then the final 3 gallon.
Water only up to 7 weeks in veg under my t-5's then in flower I just mix 5ml to 15 ml
Pure blend pro grow and water with the nutes every time until the end. Tapering up with growth and back down as they finish.
I also add 20% perlite to the soil and make sure it is fully mixed and has no clumps.
That's it. Nugs made top shelf at the dispensary and patients are all loyal and impatient. Pun semi intended.
With 600 watts in your size tent I always got good density. Over feeding can ruin that with overgrowth on some strains. They kind of come apart at the end.